IGT - Intelligent Grouping Transportation
IGT is an entirely new mode of public transport which uses computer and communication technology to group travellers with compatible itineraries onto the same (typically minibus-sized) transit vehicle, customising the road route of this transit vehicle so that it transports each traveller according to his or her itinerary, generally from door-to-door. Though conceptually simple, this idea provides an enormous range of economies and efficiencies. With individualised routing for each traveller, this form of travel can compete with the private car in terms of convenience and flexibility. The door-to-door service offers excellent personal security, protection from the weather, and conveys travellers considerably faster than conventional public transport. As a consequence of grouping many travellers into the same vehicle, IGT has the potential to substantially reduce the number of cars on the roads by as much as fourfold, and to end the proliferation of the private car. IGT thus has application in overcoming traffic congestion, parking congestion, toxic air pollution, noise pollution, and if implemented around the globe, will radically decrease greenhouse gas emissions.
Throughout the world, road traffic congestion is becoming a critical problem. Congested roads dramatically increase journey times, making travel often stupidly inefficient. Being caught in slow moving and dense traffic not only wastes time, but frequently puts drivers in aggressive moods. At the end of a car journey there is the added problem of parking: in many towns and cities finding a parking place can be very troublesome; too many vehicles compete for limited parking space. The huge amount of time lost through traffic and parking delays costs the United Kingdom an estimated £20 billion each year. There are also enormous costs for maintaining and expanding the road networks to support the increasing levels of traffic. Traffic congestion significantly degrades the quality of life for everyone - a fact not so easily quantified, but one which is directly perceived by most people in their daily lives without the need for figures or statistics.
Pollution is a further and very pressing problem of high traffic levels. Engines that run on fossil fuels (such as petrol or diesel) emit many toxic pollutants: carbon monoxide, nitrogen dioxide, sulphur dioxide, benzene, formaldehyde, polycyclic hydrocarbons, lead, and small particle matter. Some of these pollutants react together in warm sunshine to form the poisonous gas ozone, the chief component of summer smog. In London, these vehicle exhaust emissions are responsible for a staggering 90% of the air pollution.
Vehicle exhaust emissions are a substantial source of greenhouse gases. Fossil-fuel burning engines generate large quantities of carbon dioxide, a gas which though not toxic to human health, is the principal greenhouse gas implicated in global climate change. The Transport Studies Unit at Oxford University estimate that at least 25% of Britain's carbon dioxide emissions originate from transportation, and in the US the figure is closer to 33%. Road traffic may thus be detrimental to climate stability.
Traffic congestion, parking congestion, lost time and earnings, stressful journeys, road rage, degradation in the quality of life, noise pollution, air pollution, life threatening medical conditions, global warming potential: these are all problems of high traffic levels. How can traffic volumes be meaningfully reduced?
PROBLEMS OF EXISTING PUBLIC TRANSPORT
Improvement of conventional public transport facilities is frequently claimed to be the best approach for reducing traffic levels. Public transport is unarguably a vital mode of travel, and road traffic levels would certainly soar without it. However public transport, in its existing forms, can never compete with the private car. The car is at present unbeatable in terms of door-to-door convenience, all-weather comfort, flexibility of itinerary, the ease of carrying goods or luggage, personal security, and so forth.
Compared to the private car, travelling by public transport frequently requires complex pre-planning (consulting timetables, examining fare options, checking journey times, working out how to get to and from the train stations or bus stops). This planning becomes especially time consuming when travelling to new and unfamiliar destinations. For many people it will always seem easier to jump into the car. This fact is borne out by the Department for Transport's statistics: in the UK a massive 62% of all journeys take place by car, compared to only 6% by bus and a paltry 2% by train and underground railway. (Walking accounts for 26% of trips.)
These statistics further reveal that, for journeys of less than 25 miles, travelling by car is around twice as fast, on average, as the same journey by bus or train, when the overall door-to-door travel time is taken into account. Public travel takes so much longer than the car because of the necessary wait for the transport vehicle to arrive, and also because of the time consumed by trips to and from the station or bus stop, at either end of the journey.
Given these facts, it is not surprising that the car is the first choice for transport. Clearly if public travel is to be made more attractive so as to compete with the private car, the sources of this wasted time must be eliminated, as must the complex pre-planning process, the inflexibility of itinerary, and the many other problems of public transport. Furthermore, as we saw, the private car provides the bulk (62%) of the daily passenger journeys in the UK; thus the car cannot be replaced until another mode of transport is introduced to provide for this amount of passenger journeys.
INTRODUCTION TO IGT
IGT is the breakthrough solution to transport problems and traffic congestion. Its various modes of operation will radically reduce traffic levels, yet amazingly IGT requires no changes to road layouts, highway laws, existing public transport operation, or any transport infrastructures: it is a minimal-impact system, which easily coexists with other forms of transport, and other traffic control schemes. This solution places absolutely no restrictions or additional costs on motorists. In fact in one mode of functioning it actually helps drivers recoup the costs of running their vehicles. Most importantly, IGT decreases the number of vehicles on the roads, yet it does not decrease the total number of passenger journeys taking place, thus maintaining the mobility of people.
IGT has two main configurations: electronic navigation taxibus transport, and car pooling transport. IGT can run either of these configurations separately, or can run them both at the same time.
The taxibus is a revolutionary and entirely new mode of public transport, perhaps destined to become the primary mode of travel in the 21st century. The taxibus is a road transport vehicle that generally conveys passengers from door-to-door, thus providing a transport service comparable to that of a taxi cab, yet one which may profitably operate with fare costs similar to those of a bus. The taxibus is the first mode of mass public transport that can not only equal the convenience of the private car, but as will become apparent, may even exceed it.
Analysis suggests that introducing a fleet of taxibus vehicles can massively reduce the quantity of traffic on the roads: a remarkable fourfold reduction in the number of cars on the roads is obtainable. The taxibus can swiftly curtail traffic congestion, air pollution and greenhouse gas emissions with unparalleled efficacy; for these reasons it is anticipated that taxibus transportation will be rapidly adopted in towns and cities around the globe.
The car pooling configuration of IGT, though not quite as revolutionary as the taxibus, nevertheless manages to provides a very effective means of matching prospective passengers with car pool drivers having compatible itineraries, and can provide a monetary incentive to encourage drivers to give rides. Although car pooling, even in this present incarnation, is an informal mode of public transport, it can certainly help further decrease the quantity of cars on the roads.
In both taxibus and car pooling, the transportation capabilities of IGT are completely scalable: IGT can operate in a village where it might provide just a few hundred passenger journeys each day, or in a major city where it could comfortably handle 10 million or more daily passenger journeys.
Note that IGT is highly practicable, both technologically and financially. For the most part it uses existing and established technologies, most of which are already in place or already in operation; as a consequence IGT can be implemented remarkably cheaply, and without changing any of the physical or technological infrastructures of a town or city. IGT is also cheap to run, and may quite easily be operated at a profit.
BASIC CONCEPTS OF IGT
IGT rests on two transport methodologies which we shall refer to as adaptable routing and intelligent grouping.
Adaptable routing applies to vehicles whose route is completely flexible and can be modified at any time to accommodate a traveller's particular journey requirements. Adaptively-routed vehicles provide a transport service that collects a traveller from his starting point or address and conveys him to his destination point or address. This contrasts to fixed-route transport vehicles such as buses and trains which do not alter their routing to accommodate the traveller's itinerary. Ordinary taxi cabs use adaptable routing, as of course does the private car.
Intelligent grouping involves the placement of disparate travellers, who happen to have compatible itineraries, onto the same transport vehicle. Fixed-route vehicles such as buses and trains automatically use intelligent grouping; though obviously in these cases, no great intelligence is involved, as the conveyance of passengers with compatible itineraries is intrinsic to fixed-route transport vehicles.
In the case of adaptively-routed transport vehicles, however, intelligent grouping of travellers is by no means automatic and to achieve it requires precise orchestration of both travellers and transport vehicles. It is a very complex undertaking to operate transport vehicles that simultaneously use adaptable routing and intelligent grouping. Nevertheless, this is exactly what IGT does, as we shall see.
Adaptable routing is an important characteristic of IGT because it can provide travellers with door-to-door travel from their starting point or address to their destination point or address, thus creating a convenient and highly attractive mode of public transport.
Intelligent grouping is an equally important characteristic of IGT as it enables transport vehicles to carry many disparate travellers at once, which allows passenger fare costs to be kept low, and allows travellers to share the same transport vehicle.
The simultaneous union of adaptable routing and intelligent grouping achieved by IGT is fundamental to reducing road traffic as it entices travellers who might have otherwise journeyed in their own individual cars to climb aboard an adaptively-routed transport vehicle and get exactly the same door-to-door service that their cars would have provided.
In adaptively-routed transport vehicles, a set of travellers are said to be intelligently grouped when the itinerary of any one traveller does not force the transport vehicle to significantly deviate from, and thus increase the journey times of, the itineraries of the other travellers aboard the vehicle. A set of travellers can only be intelligently grouped when they have reasonably compatible itineraries.
Generally, an individual traveller will want to be conveyed on the quickest route from his embarkation to his destination (such as he would take in his own private car), rather than travel by a longer and more roundabout path in an adaptively-routed transport vehicle; the above definition states that when travellers are intelligently grouped in an adaptively-routed transport vehicle, each individual traveller's journey time from his embarkation to his destination point is not significantly increased in relation to this quickest route.
For each set of travellers, a very important parameter is one called the Compatibility Index which quantitatively measures intelligent grouping.
The Compatibility Index value for given any set of traveller itineraries expresses the average increase in each traveller's journey time that results when these travellers are grouped together and conveyed (along one of the quickest routes) in an adaptively-routed transport vehicle; the said increase is in relation to the journey time that would result if each traveller were to travel on his itinerary via the most direct route (such as would normally be taken in a private car). The Compatibility Index thus measures the degree of compatibility of a set of traveller itineraries; it measures how well a given set of travellers can be intelligently grouped into an adaptively-routed transport vehicle.
The lower the value of the Compatibility Index, the more compatible are the itineraries of the set of travellers. Perfect intelligent grouping has a Compatibility Index of 1 and, for reasons that will shortly be explained, Compatibility Index values in the range of 1 to 1.3 represent excellent intelligent grouping, with values between 1.3 and 1.6 representing an acceptable level of intelligent grouping. A Compatibility Index approaching 2 or higher represents an increasingly inefficient and a generally unacceptable level of intelligent grouping.
It can be shown that for each set of travellers intelligently grouped in an adaptively-routed transport vehicle, there exists an associated optimal transit route which represents the quickest way (or almost the quickest way) to convey the said travellers in accordance with their itineraries.
Note that the Department for Transport statistics mentioned above state that for trips of less than 25 miles, the total journey time when going by bus or train is a factor of 2 slower than the car, when the overall door-to-door travel time is taken into account.
By our definition of the Compatibility Index, the car has a Compatibility Index value of exactly 1. Thus if the taxibus can operate with a Compatibility Index as low as 1.3, then it easily beats the bus or train (which correspond to a value of 2).
COMPONENT HARDWARE OF IGT
We now introduce the component parts of the IGT system.
A transit vehicle is defined as one which is capable of carrying travellers and which is capable of being adaptively-routed on the road networks. A taxibus is a transit vehicle piloted by a professional driver; and a car pool vehicle is a transit vehicle piloted by a private driver who is travelling in this vehicle on his own itinerary.
A controlling computer system is defined as a data-processing system comprising one or more mainframe computer data-processing installations, or comprising a set of distributed (typically portable or mobile) computer processors.
A data transmission system is defined as one which facilitates transmission of data between the remotely-located components in the IGT system. A cellular telephone network is a good example of a data transmission system.
A communicator device is the generic name we shall give to the gadgets which allow people to interact with the controlling computer system. Examples include the cellular telephone and the wireless PDA (Personal Digital Assistant).
An electronic positioning system is used in its commonly-understood meaning: an electronic or computerised system that allows its users to determine their geographic location. A satellite positioning system such as the American GPS (Global Positioning System) is an example.
An electronic street navigation module provides navigational instructions which allow a transit vehicle driver to follow an itinerary (example: an in-car satellite navigation system).
An intelligent grouping module is a software module which, on the basis of traveller journey requests and on the basis of the transit vehicles available, can intelligently group travellers into these vehicles and devise optimal transit routes by which the transit vehicles can transport the travellers in accordance with their itineraries.
To ride via the IGT public transport system, individual travellers use a communicator device to submit their itinerary requirements to the controlling computer system, via a data transmission system. Typically, travellers will do this by entering their itinerary on their cellular telephone, and then simply transmit this data over the cellular network. The controlling computer system scans all the submitted itinerary requirements that it receives, and then uses its intelligent grouping module to group travellers with compatible itineraries onto the same transit vehicle. The location of all transit vehicles is known to the controlling computer system through an electronic positioning system (eg: satellite positioning). The controlling computer system creates a customised road route for this transit vehicle so that each traveller thus grouped is picked up and conveyed exactly according to his itinerary, generally from door-to-door. Travellers will be journeying simultaneously with other travellers on board. Each transit vehicle is equipped with an electronic street navigation module (like an in-car satellite navigation system) which operates in conjunction with the controlling computer system to supply street navigation instructions to the transit vehicle driver to direct him along this customised road route.
EFFICIENCIES OF SCALE
In a large city such as London, assuming IGT is running a sizeable fleet of say 10 thousand transit vehicles, the intelligent grouping module will have anything up to 3 thousand new journey requests coming in from travellers every minute. However a great virtue of IGT is that it becomes more efficient as the scale of its operation increases; that is to say, as the passenger flux (defined as the number of travellers requesting transit per unit area per unit time) increases, and the transit vehicle density (the number of vehicles per unit area) needed to handle these travellers is increased proportionately, the transportation efficiency of IGT is not only maintained, but is further increased.
This greater efficiency arises simply because the more numerous the journey requests, the greater the chance of having itineraries amongst these journey requests that are highly compatible. Consequently the intelligent grouping module becomes better able to intelligently group travellers; that is to say, better able to group travellers into transit vehicles at lower Compatibility Index values.
Two other efficiency of scale factors come into play when the number of transit vehicles per unit area increases: the first factor is a quicker response time to traveller journey requests, due to the larger number of transit vehicles in close proximity to the traveller; and the second factor is the greater ease of scheduling split journeys across two or more transit vehicles, again due to the larger number of transit vehicles available.
THE COMMUNICATOR DEVICE
Passengers and transit vehicle drivers will use a communicator device to interact with the controlling computer system. IGT uses seven practicable types of communicator device, and these are described and listed below. Note that communicator devices 1 to 4 in the list are portable or mobile units, whereas communicator devices 5 to 7 are fixed-location units. Some communicator devices in the list are specifically designed to be operated by passengers, others are specifically designed to be operated by drivers. Communicator devices 1 and 2 in the list are designed to be used by both passengers and drivers: these devices will include functionality that allows switching between passenger mode and driver mode of operation (this is useful because the owner of the communicator device may at one time be a car pool driver, but later travel as a passenger himself in a taxibus or car pool vehicle).
(1) For use by drivers and travellers: cellular telephones make excellent communicator devices, since many of the latest models allow two-way transmission of text and graphical information, and the soon-to-be-launched 3G (third-generation) cellular telephones are particularly adept at text and graphical information transmission. When used in driver mode, drivers will need to mount their cellular telephone on the dashboard for easy viewing of information whilst on the move.
(2) For use by drivers and travellers: a wireless PDA (Personal Digital Assistant), the ubiquitous electronic agenda and mini computer, can transmit data over a cellular network. When used in driver mode, drivers will need to mount their wireless PDA on the dashboard for easy viewing of information whilst on the move.
(3) For use by drivers only: a dashboard communicator device is one specifically designed for use with IGT. It comprises a display screen and keyboard, and is intended to be permanently fitted on the dashboard of the transit vehicle, such that the driver can easily see its display screen and enter information on its keyboard. Dashboard communicator devices will be standard equipment in taxibuses, and are desirable in any car pool vehicle regularly participating in car pooling.
(4) For use by passengers only: an on-board kiosk communicator device unit is a communicator device that is located within a taxibus vehicle where it can be used by passengers. These kiosks comprise a display screen and keyboard (or a virtual touch-screen keyboard, which is more robust), and will be used by passengers for such purposes as cancelling or changing their journey request or used by passengers that board a taxibus by manual hailing to specify their journey request.
(5) For use by travellers only: a roadside kiosk communicator device unit will comprise a display screen and keyboard (or a more robust virtual touch-screen keyboard), and these kiosks will be incorporated into bus stops or similar roadside structures. Kiosk communicator devices may be located both on high streets and on quieter residential streets.
(6) For use by travellers only: a web browser communicator device allows a personal computer with Internet access to act as a communicator device.
(7) For use by travellers only: regular land line or cellular telephones will offer audio communication with the controlling computer system by means of a voice recognition or touch-tone telephone interaction with the controlling computer system in a style similar to automated telephone banking. This is not the easiest way of interacting with the controlling computer system, but this method has the advantage of operating with any telephone. For people without a touch-tone phone, or for technophobes, human operator assistance could also be provided.
We use the term vehicle communicator device to denote communicator devices of type 1 or 2 used in driver mode, and communicator devices of type 3. We use the term passenger communicator device to denote a communicator devices of type 1 or 2 used in passenger mode, and to denote communicator devices of types 4 to 7.
The most popular communicator device is likely to be the cellular phone: it is anticipated that most users will use these to correspond with the controlling computer system. This is not just because cellular phones are small, portable and ubiquitous, and can send and receive text and graphics (and will have an enhanced ability to do so once the new 3G cellular networks are operational), but is also because in a few years, most cellular phones will have electronic positioning functionality built-in as standard. This is due to the American 911 mandate which requires that electronic positioning is fitted to all new cellular telephones to help emergency services locate a caller. The European Union is planning an equivalent law, the E112 mandate. In the meantime, there are cellular telephone replacement battery packs containing a satellite electronic positioning unit to upgrade existing phones. Thus the ordinary cellular telephone, that tiny gadget in everyone's pocket, becomes the perfect miniature communicator device for use with IGT.
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The electronic navigation taxibus is an entirely new mode of public transportation facilitated by IGT. The taxibus vehicle (which is typically the size of a minibus) can travel door-to-door, picking up passengers from their current location and dropping them off precisely at their destination. Just as in car pooling, the taxibus transports passengers using the principles of intelligent grouping. Unlike car pooling, however, the taxibus driver is a paid professional with no itinerary of his own, so the process of intelligent grouping is applied only to the passengers travelling in the taxibus, not to the driver.
From the passenger perspective, riding a taxibus is just like travelling by car pool, but is even easier (and much cheaper). To make a taxibus journey, the prospective traveller sends his journey request to the controlling computer system using a communicator device such as his cellular phone. The passenger must specify his desired itinerary (current location address and intended destination address), how many people are travelling on this itinerary (if there is more than one), and whether he wishes to prioritise transit vehicle speed of response or speed of journey. As with car pooling, once the controlling computer system has received this information, a new journey request record in the journey request database is created. Figure 8 in the accompanying drawings illustrates the operation of user interface on the passenger communicator device when submitting a journey request.
Just as in car pooling, when the time comes to execute this journey request (which will be straight away if the journey request is for immediate travel), the intelligent grouping module in the controlling computer system will search the transit vehicles current itineraries database in order to find a taxibus vehicle in the vicinity of the passenger that has an itinerary compatible to the passenger's destination. Out of the available taxibus vehicles, the intelligent grouping module will try to find the most efficient matching of passenger with taxibus; that is to say, to find a taxibus into which the passenger can be intelligently grouped with a good Compatibility Index.
When a suitable taxibus is found, its details will be displayed on the passenger communicator device. These details will include the estimated time for the taxibus to arrive at the passenger's pick-up point, details of the estimated journey time, and the calculated fare cost of the journey. If the passenger confirms that he wishes to travel by this taxibus, the current itinerary in the appropriate transit vehicle record is updated to reflect the new optimal transit route. As per usual, the electronic street navigation module sends the driver navigation directions to the vehicle communicator device in order to guide the taxibus along the transit route. A real-time countdown to the estimated taxibus arrival time is provided on the passenger's communicator device. Note that since the taxibus is in the vicinity of the passenger, it will generally take just a couple of minutes for this vehicle to arrive at the passenger's pick-up point.
Each taxibus has a unique vehicle identification number (or name) that is prominently exhibited at the front, on the sides, and at the rear of the vehicle. When a passenger makes a journey request, this identification number is detailed on the passenger's communicator device, to help him spot his taxibus when it appears. In addition, an electronically updatable outside display screen situated at the front of the taxibus will exhibit the principal destinations on the vehicle's itinerary. This display screen is controlled by the vehicle communicator device. Both the taxibus identification number and the outside display screen will be invaluable on busy high streets, where many passengers may be waiting for taxibuses, and where there may be several taxibuses simultaneously arriving and departing.
Just inside the entrance door of the taxibus, an electronically updatable passenger display screen (which is capable of displaying text and is which controlled via the vehicle communicator device) will clearly exhibit the user names of the passengers that are expected to board the taxibus at that point; as they board, passengers just need to glance at the passenger display screen to ensure that their user name is listed, thus confirming they have entered the correct taxibus vehicle.
The taxibus driver's communicator device will indicate the number of passengers that are expected to board or alight at any particular stop point (on most occasions it will just be one or two passengers that alights or boards). It is the driver's responsibility to ensure that he picks up and drops off the correct number of people.
A more robust method of verifying correct passenger-boarding in taxibus (and car pool) travel would employ smart card technology wherein each passenger would carry a personally-issued smart card, and this card would be remotely scanned (without needing to take the smart card out of one's wallet or bag) by a card reader in the taxibus vehicle communicator device as the passenger boards, thus confirming a correct passenger pick-up. Using such a system of smart cards, as each passenger boards the taxibus vehicle, both the taxibus driver and passenger will see a correct pick up confirmation sign appear next to the passenger's user name on the passenger display screen.
Just as in car pooling, payment of taxibus fares is handled automatically by the controlling computer system, and the amount of the fare is debited from the user's system-administered monetary account. This allows passengers to board the taxibus without fumbling for coins or travel passes, thus minimising the vehicle's stop time.
Once on board, the passenger will typically share his trip with several other fellow travellers. Because it picks up and drops off other passengers en route, the taxibus is not quite as quick as the car. But taxibus travel is much quicker than an excursion on a regular bus. Bus journeys are lengthy because of the walk to and from the bus stops, the time spent waiting for the bus, and the time it takes for passengers to board and alight at each of the bus stops along the route. The door-to-door service of the taxibus operates with much greater rapidity and convenience. The controlling computer system will ensure that all taxibuses follow a reasonably linear trajectory, pressing forwards towards their destinations at all times. The controlling computer system will allow a taxibus to pick up new passengers if they are located ahead on its itinerary, but generally not if the taxibus must double back in order to get them, as this would be inefficient (such passengers will be placed on another taxibus).
Passengers travelling on a taxibus are informed when their destination is imminent. Inside each taxibus, one or more large interior display screens capable of displaying textual information will be mounted so that they are visible to all passengers within the vehicle; these screens, which are controlled by the vehicle communicator device, will show the geographic name of the upcoming taxibus stop points (with a format such as 'NEXT STOP: Kensington High Street W8 6NA'). Additionally, these interior display screens will list the user name of the passenger or passengers who should alight at the displayed destination. Passengers who carry their own portable communicator device (such as a cellular phone) will have the general progress of their personal journey exhibited on this device, including advance notice of their upcoming destination.
Note that a passenger can ask the driver to stop the taxibus at anytime should he wish to disembark before his specified destination.
ADVANTAGES OF THE TAXIBUS
The taxibus does something that even the private car often cannot: it delivers passengers exactly to their destination. In most cities, when a parking space is eventually found for a private car, it is often several minutes walk away from the intended destination. This is a problem in bad weather, in areas of high crime rate, and for single women late at night. Leaving a car unattended and out of view can also increase the risk of theft or vandalism. The door-to-door service of the taxibus has an inherent level of security that neither the car nor conventional public transport can beat. A taxibus can be used, for example, to safely transport children to school on a door-to-door basis, so that parents need not worry about the school run each morning (which in itself will clear a great deal of traffic from the roads in the UK: just before 9 am in urban areas, an astounding one car in every five is taking children to school).
The door-to-door service of the taxibus is also invaluable for the frail, elderly or disabled. Many towns in the UK have a 'dial-a-ride' service for people with a mobility impairment, which provides minibus door-to-door travel in the local district; typically these rides must be booked by telephone a day in advance. IGT can subsume the dial-a-ride service: the taxibus offers more efficient routing, and can be requested just minutes before required; the existing dial-a-ride minibus vehicles, which are specially designed for use by mobility-impaired people, can be incorporated straight into IGT as taxibuses simply by fixing a communicator device for the driver on the dashboard (and installing a passenger display screen, an interior display screen, and painting a vehicle identification number (or name) on the outside of the minibus).
By default IGT will marshal a rapid response to passenger journey requests, providing a taxibus to pick up passengers within minutes; however it is also possible to submit a journey request that books a taxibus trip some time in advance, using pre-order booking. A pre-order booking is just like an ordinary journey request, except that the passenger must additionally specify the precise time in the future that she wishes the taxibus to come and collect her for the journey. It is also possible to organise a regular order booking for taxibus trips. A regular order booking is a journey request which is automatically executed at a specified time, and which is repeated on a specified regular basis. Regular order bookings are very useful for people who commute to and from work at the same hour each day. When commuters place a regular order booking with the controlling computer system, a taxibus will automatically collect them from their home on the days and the times they have specified for the journey to work, and likewise for the return journey if so requested. Regular order journeys have many other uses: for children travelling to and from school each day, for regular visits to the gym after work, and for any trip or journey that is routinely undertaken. Regular order bookings have advantages both for passengers, and for the taxibus system. For passengers, it saves them the trouble of ordering a taxibus every time; the taxibus will arrive automatically as specified. For the controlling computer system, foreknowledge of passenger journey requirements can allow for a more efficient routing of the taxibus fleet.
It is anticipated that the taxibus will be more convivial and community-oriented than any other means of travel, because the controlling computer system will naturally tend to group like-minded passengers in the same vehicle. Football fans, theatre goers, concert crowds, conference attendees, tourist attraction visitors, and so forth, will all tend to be grouped with their own kind into the same taxibus, simply because this is the most efficient way of transporting people headed for the same destination. It would even be possible to program the controlling computer system to deliberately exaggerate this social grouping effect. This might be done not just for conviviality, but also for security: school children, for example, would benefit from being exclusively grouped together in one taxibus for safer travel.
The taxibus is an interesting way of travelling. Even for commuters going to the same destination every day, the taxibus will generally run a different route variation on each journey, depending on the itineraries of the other passengers on board. This means that on every journey the traveller may see something new: a street he has not been down before, or an area of the city he has never seen. Also, because the taxibus takes the most efficient route and because the system knows all the back streets, travelling by taxibus is a great way to learn new short cuts.
There are so many benefits to taxibus travel. There is the great feeling of freedom the taxibus gives: it takes you exactly where you want to go, and wherever you are, a taxibus is always available whenever needed. As a taxibus traveller, there is no need to carefully monitor the amount of alcohol you are drinking, as car drivers must. This in itself may revolutionise the social lives of many people, but more importantly, a hidden benefit of introducing a comprehensive taxibus service might be a marked decrease in alcohol-related road accidents.
The taxibus is particularly fast and convenient for travel to an unfamiliar address: instead of pre-planing the trip using a street atlas, you simply submit a journey request for travel to this address, and the taxibus will drop you right outside.
The taxibus brings simplicity to public travel, offering an easy way of taking a trip. Ease and simplicity are partly why the private car remains so popular: with the car you just get in and go. The taxibus is equally uncomplicated: state your destination, and let the taxibus take you there. One must reflect for a moment to really appreciate the almost magical power of taxibus transportation. With nothing but a cellular phone, you press a couple of keys, and a taxibus appears just minutes later, ready to whisk you away to the destination you selected.
THE TAXIBUS FLEET
The taxibus fleet will contain a diversity of types and sizes of vehicle. Vehicle size brings advantages and disadvantages. Larger vehicles can transport more people (and using just one driver, so it is also more economic on personnel); but higher passenger numbers equate to longer journey times, as a result of the extra pick-ups and drop-offs en route. By contrast, smaller vehicles transport less people, but do so more rapidly. Larger vehicles are efficient at transporting passengers that have identical embarkation or destination points, for example, passengers travelling from an airport to city centre hotels, or passengers travelling to a large public event such as a music concert or football match. Larger vehicles may be more appropriate for inter-city travel. Smaller vehicles are better at driving down narrow residential streets, picking up and dropping off passengers from their homes. It is thought that taxibus fleets in cities should comprise mainly smaller-sized vehicles, in the range of 4 to 12 passenger seats (in other words, the size of a multi-purpose vehicle or people carrier, up to the size of a minibus).
The journey range of each taxibus vehicle may vary. Some vehicles might be restricted for use within specified suburban areas; other vehicles might cover the whole of a city; still others might run from city-to-city or cover an entire country.
Occasionally a passenger's journey may be split into two legs, using two different taxibus vehicles. Typically, passengers travelling city-to-city by taxibus may have their journey thus split: a local taxibus vehicle first collects the passenger from his address, and later the passenger is transferred to another (perhaps larger) taxibus vehicle for the inter-city portion of his journey. The controlling computer system will however always try to transport passengers on a single taxibus if possible.
An enhancement to further improve the efficiency of IGT would involve the controlling computer system deploying its taxibus fleet according to the time of day. During commuter rush hours the controlling computer system will tend to pull all its taxibus vehicles into operation; at quieter times such as during the night, many taxibuses will rest in their depots (small taxibuses might be parked outside the residence of the taxibus driver). In the morning rush hours, the controlling computer system will ensure that plenty of taxibuses are mustered around the suburban regions ready to take passengers into the city centre. In the evening rush hours, the controlling computer system will orchestrate the reverse. The controlling computer system will maintain a database of the statistically averaged passenger flux in all regions of the city, for all times of day, and for all days of the week. (The passenger flux from a given area is defined as the number of passengers per unit time requesting taxibus transport in that area). Using this passenger flux database, the controlling computer system will pre-emptively marshal its taxibus fleet so that the vehicles are fully prepared and positioned to meet temporal variations in travel demands (the controlling computer system will generally pre-emptively re-position taxibuses that are currently empty). The controlling computer system will also act on any notice that it is given of large public events, pre-emptively marshalling its fleet in order to handle the crowds.
Later in the evening and at night the controlling computer system will withdraw larger taxibus vehicles from the roads, keeping just the smaller taxibuses in operation. This will save fuel, keep noise levels down, and further decrease road congestion, as smaller vehicles take less space and cause less blockage when pulling over to pick up or drop off passengers. One of the problems with regular buses is that large vehicles are needed to deal with the peak hour passenger flux, but at other times these vehicles remain half empty. The taxibus fleet responds much more dynamically to variations in passenger flux.
Who would run the taxibus fleet? Many operators could be accommodated by franchising different organisations to run taxibuses. As long as each taxibus vehicle runs under the control of the controlling computer system, it does not matter who owns or drives the vehicle. Even an individual driver may purchase a taxibus vehicle and enter into a franchise; existing taxi cab or mini cab drivers might consider this. At the other end of the spectrum, large companies might operate a fleet comprising thousands of taxibus vehicles. IGT can accommodate all.
The controlling computer system may also accommodate specialist taxibuses: for example, large shopping centres or supermarkets might operate a small local fleet of taxibuses which would respond only to passengers headed for the shopping centre. Containing ample space for purchases, these taxibuses might even offer free rides to customers. Other types of specialist taxibuses could include ones designed for transporting particularly large or heavy items. There is even the possibility of including first class taxibus vehicles in the fleet. First class vehicles would levy higher fares, but would contain larger and more comfortable seats, and provide additional services such as for example airline style back-of-seat Internet access terminals. A first class taxibus vehicle might even be designed to comprise several small compartments which are separated or semi-separated from each other, thus providing greater privacy for passengers carried. In general, the greater the diversity of taxibus vehicles operating, the better IGT is able to satisfy specific transport requirements.
Taxibus vehicles could advantageously be powered by hydrogen fuel cell engines. In certain configurations these engines are completely pollution-free: their exhaust product is actually pure water vapour. No pollutants or greenhouse gases are emitted. Hydrogen fuel cells create electricity which then drives an electric motor: vehicles with these engines thus run very silently. Large investments in developing hydrogen powered vehicles have been made, and they are fast becoming a viable technology. The main problem is the lack of fuelling stations. However, proponents for hydrogen fuel argue that at this initial stage, the rollout of fuel cell technology is ideally suited to public transport vehicles. Such vehicles are usually refuelled at their depots: this small number of depots can be equipped with hydrogen fuelling stations at minimal expenditure - thus providing an extremely cost effective way of cutting air pollution and greenhouse gas emissions.
THE TAXIBUS COMBATS PARKING CONGESTION
We have seen that the inherent efficiency of the taxibus arises from adaptable routing and intelligent grouping, with each taxibus typically conveying several disparate passengers at once on a door-to-door basis. By contrast, the private car, which occupies pretty much the same road space, typically carries only the driver. Worse still, each solo driver has a whole exhaust emitting engine to himself, which pumps out pollutants and greenhouse gases. The private car is thus indicted on transportation inefficiency, and excessive emission of undesirable exhaust products.
However the private car harbours a third and equally disturbing inefficiency: the average automobile is only utilised 10% of the time, with the typical car driven for less than 1.5 hours each day.
The rest of the time, which is 90%, a private vehicle lies idle, parked, and taking up space. Considering this inefficiency it is not surprising that the kerbs on most main roads and residential streets are crammed with parked cars. If the usage efficiency of cars were 100% then clearly no parked or stationary vehicles would be seen anywhere, apart from when dropping off or picking up travellers or delivering goods. This is self-evident, but it is worth repeating this point because it is normally overlooked: the reason our streets are so overburdened with parked cars is not just a factor of the level of vehicle ownership, but also a factor of vehicle usage efficiency, which as stated is a meagre 10%. A simple equation describes parking congestion:
Number of Parked Vehicles =
Number of Vehicles Owned X (100 - Usage Efficiency) ÷ 100
We have become so accustomed to seeing parked vehicles clogging up towns and cities that we assume this is an unavoidable consequence of enjoying the convenience of motor transport. But it is not: the above equation implies that if vehicle usage efficiency is increased, the number of parked vehicles will decline proportionately, and that increasing the usage efficiency to 100% will actually result in having no parked vehicles in the streets whatsoever. A taxibus vehicle's usage efficiency generally tends towards a perfect 100%, because the controlling computer system tries to ensure that all of the taxibus's time is dedicated to active transportation. Once the taxibus delivers a passenger, it does not remain idle, but continues conveying other passengers. The private car, on the other hand, tends to be quite useless once the driver has departed.
In urban areas, the fact that the private car must be parked when it arrives at its destination can be considered a design flaw in this mode of transportation. Consider the amount of time that is lost looking for parking places, the parking fees that must be paid, and the inevitable parking fines, vehicle clamping and tow-away costs, the cost of building massive multi-level car parks, the running of controlled street parking, of buying parking area land for shopping centres and sports centres, and so forth. Still further expense results from salary costs for traffic wardens and other staff to regulate these parking zones.
Even when drivers are on the move, parking still affects their journey: in many cities, most smaller roads are now effectively reduced to one lane due to parked cars on both kerbs, and during any trip, drivers are frequently forced to pull over into a gap between these parked cars in order to let oncoming traffic squeeze past. Parked vehicles are cholesterol on the road arteries of our cities.
In a future where the electronic navigation taxibus has taken over from the car as the primary form of travel, and the number of privately owned vehicles has fallen, parking congestion will be of historical interest only, and free parking spaces will be abundant. Perhaps the streets will never quite revert to an era when they were largely clear of parked vehicle clutter, but with a comprehensive taxibus service in place, this epidemic of idle kerbside automobiles can be abated.
In such a future of streamlined taxibus transportation, the roadside parking meter would become redundant; parking meters could be advantageously converted into mini roadside kiosk communicator devices on which passengers can request taxibus rides, and by which they can wait for their taxibus to arrive.
GREATER LONDON CASE STUDY OF THE TAXIBUS
Let us examine how an electronic navigation taxibus fleet compares to existing forms of transport. We shall take Greater London as our case study. For each 24 hour period in central and outer London, around 25 million passenger journeys take place. These divide modally as follows.
9 million Private Car (as Drivers)
6 million Private Car (as Passengers in above)
4 million Bus
2 million London Underground
2 million Walking
1 million Train (Surface Rail)
Source: Department for Transport. Figures have been rounded.
Other modes of travel in Greater London (motorcycle, taxi cab, mini cab, bicycle) are fairly negligible in comparison. The relative importance of these transport modes is somewhat reversed as far as peak-hour travel to and from central London is concerned: morning peak hour (7 am to 10 am) passenger journeys into central London divide modally as follows.
0.5 million Train (Surface Rail)
0.4 million London Underground
0.1 million Private Car (Either as Driver or Passenger)
0.05 million Bus
Source: Department for Transport. Figures have been rounded.
How would a London-based electronic navigation taxibus fleet compare? Consider a taxibus fleet of just 10 thousand vehicles. Assume an average vehicle occupancy of 6 passengers and a typical passenger journey time of 20 minutes (average journey length in Greater London is 7 miles and the average suburban speed of 20 mph; this corresponds to a journey time of about 20 minutes when the Compatibility Index is low). A quick calculation shows that this taxibus fleet would complete 180 thousand passenger journeys every hour. In a 24 hour period, the fleet could in principle handle 4.3 million door-to-door passenger journeys, which is a formidable number.
We can compare this to London's 6 thousand buses, which carry 4 million passengers each day, mainly in double-decker vehicles having a capacity of around 80 passengers. Another point of reference is London's 20 thousand licensed taxi cabs which, throughout every 24 hour period, manage to transport 0.5 million passengers.
How will these 10 thousand taxibuses cope, theoretically at least, with the 7 am to 10 am rush hour commute to central London? Assuming, during these rush times, an average taxibus occupancy of 8 passengers and an average commuter journey length of say 40 minutes, then a simple calculation shows that the taxibus fleet will manage to transport over 0.36 million commuters during these three hours. This is a very impressive figure, almost equalling the performance of the entire London Underground system during the same time period.
The incredible power of IGT becomes even more apparent if passenger journeys from car pooling are also taken into consideration. There are 9 million private car journeys made each day: if these drivers were to offer a car pool ride just once in every five journeys they make, this would add up to nearly 2 million car pool passenger journeys daily. Again for comparison, this is a figure equal to the daily total of passenger journeys on the London Underground.
What about the operating profit and the running costs of the taxibus fleet? The major running costs will arise from driver wages: this fleet of 10 thousand taxibuses will require around 30 thousand drivers working in 8 hour shifts to keep these vehicles on the road 24 hours a day, 7 days a week (based on only a reduced taxibus service running at night). Assume each driver costs a total of £25,000 per year for salary and other costs, then the wage bill will amount to £750 million annually. Fuel costs for this fleet can be calculated at £300 million a year (based on the fleet using diesel fuel, and each taxibus giving around 20 miles per gallon).
Further costs will be incurred from vehicle servicing and maintenance, and the expenditure of running the controlling computer system. Telecommunications costs should be minimal, since only low volumes of data are transmitted. Driver training costs will be low: a standard driver's licence will suffice since most of the taxibus vehicles will be not much larger than a regular multi-purpose vehicle or people carrier type of motorcar. Taxibus drivers will not need to have knowledge of the street layouts, as electronic street navigation is provided at all times.
What about the sales revenue generated? Setting the taxibus passenger fare at a modest 15 pence per mile, and assuming an average vehicle occupancy of 6 passengers, with an average vehicle speed of 20 miles per hour, then the daily (24 hour) revenue collected by the fleet will be £4.3 million. This adds up to nearly £1.6 billion a year, which should easily cover the running costs of the taxibus fleet.
Regarding the capital cost of introducing such a taxibus fleet: most of the investment will arise from buying taxibus vehicles; the computer technology that runs IGT is relatively cheap. Assume each taxibus vehicle costs £30,000, which is the typical current price of a multi-purpose vehicle or minibus: it will then require a capital investment of £300 million to purchase a fleet of 10 thousand taxibus vehicles. Not only is this a modest figure by transport budget standards, but this amount might even be accommodated within the annual profits generated by such a fleet.
It is interesting to examine the figures for a larger taxibus fleet. Suppose the fleet is increased to 30 thousand taxibuses. This requires a capital investment of £900 million to buy the vehicles, a team of 90 thousand drivers to keep them moving, £2.25 billion a year in driver salaries, and £900 million a year on fuel; such fleet will generate an annual revenue of £4.7 billion, and provide almost 13 million door-to-door passenger journeys each day - a figure that is close to the daily total of passenger journeys made by private car in London. Thus a fleet of 30 thousand taxibuses can do more or less the same job as London's 2.3 million privately-owned cars. We could therefore dispense with many of these cars. This possibility is not just a utopian vision: it is a glimpse at what cities of the future will be like. The taxibus has the potential to transform urban life and the city landscape. Car manufacturers need not worry unduly about the prospect of a decline in private car sales: due to the high workload of taxibuses, which will be in operation 24 hours a day, it is expected that taxibus vehicles will wear out quickly, and will require frequent replacement.
Does it make economic sense for a Londoner to sell his car and travel primarily by taxibus? Ownership of the average car can be costed at around £10 a day inclusive of fuel, road tax, insurance, servicing, maintenance, and vehicle depreciation, but exclusive of parking. The average vehicle covers a distance of less than 30 miles each day with an average occupancy of 1.4 travellers: this equates to a cost of 24 pence per person per mile, excluding any parking fees. Comparing this to the 15 pence per mile taxibus cost, this analysis suggests that it does make good economic sense to sell the car and adopt the taxibus, although the precise economics will greatly depend on individual circumstances. Families with children may not be so keen to sell the car, since the car becomes more economically viable when there are more travellers. A special discount on taxibus fares might be offered to family groups in order to make the taxibus more financially appealing to families.
The ultimate objective of the taxibus is not to eliminate the private car, but to seduce people away from the car by providing a taxibus transportation network that the public will come to view as a much more convenient and convivial way to travel. The taxibus aims to compete with - and beat - the private car in terms of transport excellence; winning over clientele through its manifest superiority.
Note: the above transportation and financial performance analysis of the taxibus is based on an assumed average vehicle occupancy of just 6 passengers; if higher average vehicle occupancies are achieved, say 10 passengers per vehicle for example, then all the above performance figures will be proportionally improved.
TAXIBUS RESPONSE TIMES
The success of the electronic navigation taxibus as an everyday means of transport will crucially depend on the time a prospective passenger has to wait for a taxibus to arrive. To compete with the 'jump in and go' immediacy of the private car, it is felt that a taxibus must appear within three minutes of a passenger making a journey request. Is such a rapid response feasible? Some simple analysis can answer this question. Again we shall take Greater London as our case study.
The total area of Greater London is around 610 square miles. Assuming we have a fleet of 10 thousand taxibuses more or less evenly spread across this area, this gives an average vehicle density of 16 taxibuses per square mile. Department for Transport statistics indicate that the average road speeds in the suburbs are around 20 mph, and 11 mph in the central London area. Thus in the suburbs, in order for the typical taxibus response time to be three minutes or less, the responding vehicle must be situated no further than one mile away (since at the average suburban road speed of 20 mph, it takes three minutes to travel one mile). How many taxibuses are there within a one mile radius of any waiting passenger? The answer is simply the area of a one mile radius circle (which is 3.142 square miles) multiplied by the taxibus vehicle density per square mile. This gives 16 x 3.142 = 50 taxibuses. This is a fair number of vehicles, and since these 50 taxibuses will have a wide variety of itineraries, there is a high chance that one or more will be travelling in a direction compatible to the passenger's desired destination (this probability also depends on the closeness of the passenger's destination; the closer the destination, the higher the chance; note that the average journey length in London is just 7 miles).
In central London, the average speed is 11 miles per hour, so the three minute response time will encompass a smaller circle: one of just over half a mile in radius. This circle is smaller than the suburban one: its area is only 1 square mile - thus containing fewer taxibuses. However the controlling computer system could be configured to maintain central London taxibus densities at a higher level, and this greater abundance of vehicles will ensure that a three minute response time is attained, even if the road speeds are lower. Of course, if traffic congestion falls due to the ubiquitous success of the taxibus, then average road speeds will improve, and so speed up response times all round.
This simplified analysis is no substitute for a more in depth mathematical modelling of taxibus response times, but it does strongly suggest that a three-minute response is eminently feasible.
If we relax the constraints and allow the passenger's journey to be split into two legs on different taxibus vehicles, then there is almost certainly going to be a suitable taxibus within three minute's proximity to run the first leg of the journey. If the taxibus fleet is increased from 10 thousand to 30 thousand vehicles, then the taxibus density increases proportionately, yielding a remarkable 150 taxibus vehicles within a three-minute radius of a passenger, thus making the desired response time still more feasible.
In certain travel circumstances, such a rapid response time might not be so critical. When a regular taxi cab or mini cab is ordered over the phone, for example, the taxi normally arrives around 10 or 15 minutes later; in many situations this time scale is perfectly adequate. In taxibus travel, there are advantages for passengers who are more flexible regarding the arrival time of their taxibus: such time flexibility gives the controlling computer system more opportunity to find a taxibus with a near-perfect itinerary match to the passenger. This means that although the passenger may have to wait a little longer for her taxibus to arrive, the journey on the taxibus itself will be quick and efficient, due to good itinerary matching.
When ordering a taxibus or car pool vehicle, passengers should be given the choice of prioritising the transit vehicle speed of response or the speed of journey. Perhaps most passengers will prioritise the speed of response, preferring to get aboard a vehicle as quickly as possible (which is desirable if the prospective passenger is waiting in the street). However passengers who prioritise the speed of journey will find that, once aboard their transit vehicle, they will be more speedily delivered to their destination (perhaps this is a better option for prospective passengers waiting indoors). When speed of response is prioritised, the controlling computer system would aim to get a transit vehicle to pick up the traveller within 3 minutes of the departure time specified in the journey request; that is to say, the latest acceptable pick-up time for the traveller will be 3 minutes after this departure time, the total traveller pick up time window thus being 3 minutes. When speed of journey is prioritised, the traveller pick up time window is extended to 15 minutes, starting from the specified departure time.
TESTING THE TAXIBUS CONCEPT
The taxibus is an entirely new form of transport, and must initially be tested on a small scale, firstly to examine its overall functionality, and secondly to optimise certain design and operational parameters.
Implementing the car pooling mode of IGT is a simple and inexpensive way of testing its general functioning: no vehicles need to be purchased, so the car pooling mode can be implemented at a very low cost. Once car pooling is up and running, it will yield valuable data on how IGT operates in reality. However, there are many differences between car pooling and the taxibus, and the taxibus transportation system needs to be tested separately.
Perhaps the cheapest way of testing the taxibus is by means of computer simulation of a city's travel networks. The software for such a simulation could be written without much difficulty, and would be extremely useful for observing the effects of adjusting various parameters, such as the number of taxibuses in the fleet, the passenger capacity of each taxibus, and the operational characteristics of the intelligent grouping module. By means of this simulation, optimum parameter values can be determined before setting up a real taxibus service.
Subsequent to computer simulation tests of the taxibus, the next step would be to implement a taxibus service on a small scale. This might best be accomplished in a city of less than half a million inhabitants, wherein a relatively modest fleet of taxibus vehicles can cover the whole town. It is very important to implement a saturation level of taxibus vehicles in any test. Saturation level is defined as the minimum taxibus vehicle density that can consistently provide a three minute response time to journey requests. If the taxibus density is below the saturation level, then the average response time to passenger journey requests becomes longer. Slow response times will put people off using the taxibus: nobody is going to find the taxibus quick and efficient if it takes 20 minutes for the vehicle to arrive. Thus IGT must be tested at saturation capacity in order to investigate how the general public take to the taxibus.
A small scale test is even possible in large cities. This is achieved by providing a saturation level, 24 hour taxibus fleet to a particular suburb in the city. Just a few hundred taxibus vehicles will be needed for saturation coverage. Travel on these taxibuses would be restricted to journeys within the selected suburban area, and journeys from the suburban area to the city centre and back. These limited transport options will not be able to accommodate all the travel demands of these people, but should encompass a good percentage of their normal journeys - enough to make the test meaningful.
Small scale testing in a large city may also be achieved by confining the taxibuses to the central area. The central London region, for example, bounded by the Inner Ring Road covers just eight square miles. A fleet of 200 vehicles constrained to this zone would yield a density of 25 taxibuses per square mile, which should be sufficient.
Note that the vehicles used for testing need not be specially designed or purchased. Large cars and minibuses can be employed. For testing purposes, the only essential modifications required are the fitting of a communicator device on the dashboard, and the displaying of a vehicle identification number (or name) on the outside of the taxibus. However, if the budget is available, a fleet of new, purpose-built vehicles will obviously make a better impression on the public.
INCLUDING REGULAR TAXI CABS
Regular taxi cabs are readily included in IGT, and there are two ways a taxi driver can benefit. In the first, the taxi driver uses IGT just to acquire customers, in a manner similar to the existing 'radio taxi' passenger procurement system. In this mode of operation, when a passenger makes a journey request, his communicator device, in addition to detailing the currently available taxibus and car pool travel options in the passenger's vicinity, will also detail the taxi cab options available. Should the passenger select a taxi cab option, the controlling computer system will respond accordingly: the journey request will be detailed on the selected taxi driver's communicator device, and if the taxi driver accepts the journey request, the controlling computer system will guide him to the passenger, just as it does with car pool drivers. This taxi mode of operation is not strictly speaking an application of IGT since it does not follow the principle of intelligent grouping; nevertheless this taxi mode can easily be provided by the controlling computer system, and will be helpful for both taxi drivers and their passengers.
The second way a taxi driver can benefit from IGT is to operate his vehicle as a taxibus. In this taxibus mode of operation, the passenger fares charged will be lower - being priced similar to car pool fares; however the taxi driver will be conveying perhaps three or four disparate passengers at once, so their concurrently metered fares will add up to an amount which is comparable to a normal taxi fare. It is entirely up to the taxi driver how he wants to operate: he can function in taxi cab mode or in taxibus mode. The mode of operation can be switched at any time; the taxi driver would select the mode in order to maximise his business and profit.
Even if taxi drivers prefer to remain as regular cabs, operating only in taxi cab mode, it is anticipated that IGT will deliver taxi drivers more custom. Many prospective passengers using IGT will want to take the first and fastest transport option available: this will always be the taxi cab. Why? Because with taxibus or car pool travel there are two requirements to satisfy: the transit vehicle must be in proximity to the passenger and the vehicle must have itinerary commitments compatible to the passenger's itinerary. With the taxi cab there is only one constraint to satisfy: proximity. Thus a taxi cab vehicle will generally be the first available, and because it does not pick up other passengers en route, it will generally be the fastest available. For these reasons it is believed that IGT will deliver more business to taxi cabs. Whether the taxi driver's fee is paid automatically into his system-administered monetary account, or paid in cash within the cab, is a question that needs further consideration.
One advantage IGT offers the taxi driver is the ability to accept or decline incoming journey requests on the basis of the passenger's specified itinerary - this itinerary will always be detailed on the taxi driver's communicator device. This is useful when the taxi driver is finishing his working day and is about to return home: in these circumstances he can select a passenger with a destination close to his home, and thus conveniently include one more fare before he ends his shift.
For mini cab drivers too, IGT holds promise. Instead of illegally soliciting business on the streets, mini cab drivers might find it much more rewarding to work as a professional taxibus driver. Though many mini cab drivers often have a less than complete knowledge of the road layouts, this does not present a problem since taxibus drivers just need to follow the electronic street navigation directions detailed on the vehicle communicator device.
INCLUDING EXISTING MODES OF PUBLIC TRANSPORT
Most of the difficulties and time wasted using existing modes of public transport arise from the trips to and from the transport departure and arrival points (train stations, bus stops, and so forth). It is anticipated that just by introducing a taxibus service - which can cheaply and efficiently provide these trips - the general public will start to make better use of existing public transport, especially the railways, which offer fast long distance travel.
However, it is thought that in the long term, existing public transport modes such as bus, train, tram, coach and metro may also be included in the controlling computer system of IGT. These existing modes of transport are not strictly speaking an application of IGT, since they are fixed route rather than adaptively-routed transport vehicles. Nevertheless these existing public transport modes can be advantageously incorporated into the controlling computer system of IGT, and in this section we outline how this can be done.
In order to operate with existing public transport, the controlling computer system of IGT must have real-time knowledge of the current location, routing, and destination of all participating public transport vehicles (this may require the installation of communicator devices in each transport vehicle, and/or linking up to any computer systems that help control these transport vehicles). With this information available, when a traveller submits a journey request, the controlling computer system of IGT will be able to provide the traveller with details of the various transport options that enable the traveller to get to his desired destination; the controlling computer system will detail these various transport possibilities on the traveller's communicator device.
Fixed-route transport vehicles such as bus, train, tram, coach and metro cannot divert in order to pick up or drop off passengers; so if a passenger opts to travel by these modes of transport, he will be provided with a walking route to the appropriate bus stop or train station. Passengers using a roadside kiosk communicator device will be shown a map of this walking route on the kiosk screen, and passengers that have a portable electronic positioning communicator device (such as a cellular phone) equipped with electronic positioning will be given electronic street navigation directions in real time as they walk to the station or bus stop. On arrival at the station or bus stop, the controlling computer system will inform the passenger what ticket to buy, and which transport vehicle to take. The controlling computer system will also inform the passenger at what point he or she must alight from the vehicle. Passengers carrying their own electronic positioning communicator device will even be prompted to alight from their transport vehicle just before their destination station or bus stop comes up (provided, of course, their communicator device is within range of a signal). After alighting, further walking directions from this disembarkation point to the destination address are available on the passenger's communicator device, if needed.
Note that the taxibus and car pooling configurations of IGT operate by means of a self-contained computer system which runs entirely independently, without any interface to the software systems of existing transport systems. However if existing transport modes are included, this adds considerable complexity, since the controlling computer system of IGT will need to interface with the computer systems of these various forms of existing public transport. For this reason, it is thought that the integration of existing transport modes into the controlling computer system should be deferred, and not form part of the immediate implementation of IGT. In the long term, however, such an integration of transport modes will be enormously convenient to travellers, as the next section describes.
AN INTEGRATED MULTI-MODEL TRANSPORT SYSTEM
Should existing public transport modes such as bus, train, tram, coach and metro be incorporated as described above, then the controlling computer system of IGT will become an incredibly flexible transportation nerve centre, yet one which anyone can access using a communicator device such as a cellular telephone.
Once existing public travel modes are integrated into this controlling computer system, prospective passengers will have a comprehensive range of travel possibilities instantly at their disposal. For example, consider a passenger in London wishing to travel from Kensington to Islington. Having submitted his journey request to the controlling computer, the passenger might have the following travel options exhibited on his communicator device:
These detailed travel options are based on the passenger's current location, his desired destination, and the current availability of transport vehicles in his vicinity. These options detail the estimated wait before the transport reaches the passenger, the estimated journey time, the cost of the journey, and the estimated time of arrival at the destination. For taxibus, car pool and taxi cab modes of transport, the 'Wait' estimates the time it will take for the vehicle to get to the passenger (in this example the taxibus is estimated at two minutes away). For bus and Underground modes, the 'Wait' estimates the time it will take for the passenger to walk to the transport (in this example the Underground station is 6 minutes' walk away, and at the other end of the journey, there is a 7 minute walk from the Underground station to the final destination).
FROM: 263 Kensington High Street W8 6NA TO: 116 Upper Street N1 1AE
Transport Wait Journey Cost £ Arrival Taxibus 2 mins 32 mins £ 1.05 11:34 am Car Pool 4 mins 25 mins £ 4.50 11:29 am Bus 0+1 min walk 56 mins, 2 legs £ 4.50 11:57 am Underground 6+7 min walk 30 mins, 2 legs £ 1.60 11:43am Taxi Cab 1 min 24 mins £ 14.00 11:25 am
Time Now: 11:00 am Passengers: 1 Distance: 7 miles
All travel options shown on the communicator device are available to the passenger. Should he select one, the controlling computer system will proceed with that choice, either organising a transport vehicle to collect him, or guiding the passenger to walk to the transport embarkation point. In car pooling, note that vehicle availability is unconfirmed until the driver accepts the fare: when a passenger selects car pooling, the passenger's journey request is sent to the car driver, who may or may not accept it; if he does not accept, the controlling computer system will try to find another car pool vehicle for the passenger. The same unconfirmed status applies to taxi cabs too, since the controlling computer system gives taxi drivers the choice of accepting or declining passenger journey requests. In reality, taxi drivers will generally accept passenger journey requests because these drivers earn their living from providing carriage.
As the figures indicate, carriage by car pool is more expensive than travel by taxibus. This is because adequate remuneration is needed to provide an incentive for car pool drivers to carry passengers, and also because car pooling is generally quicker than the taxibus: car pool vehicles carry fewer passengers (usually just one or two) so there are fewer pick-ups and drop-offs en route.
Like the taxibus, the cost of a car pool trip is calculated according to the distance travelled. However a second costing factor is also added to the car pool pricing equation, this factor based on the additional time the driver spends in picking up and dropping off his passenger. The additional time is called the "diversion time". If the diversion time is large, the passenger fare will increase correspondingly in order to fairly remunerate the driver for his trouble. Because of this diversion time factor, shorter car pool journeys often have a higher cost per mile compared to the taxibus. However long car pool journeys can be relatively inexpensive, approaching taxibus fares, because, for these lengthier trips, the diversion time factor will generally be less significant than the distance-travelled factor.
With the controlling computer system having real-time knowledge of the current location, routing, and destination of all participating public transport vehicles, it is possible to program the controlling computer system to respond to a traveller's journey request in a dynamic and flexible way, employing the most suitable travel options available at the time, and splitting a traveller's journey across different transport modes if this can expedite the trip. For example: a traveller may submit a journey request specifying that she wishes to travel as rapidly as possible from a suburban address in London to an office in central London during the morning rush hours. The controlling computer system calculates that the quickest way of getting to central London at that time is by Underground, and thus arranges for a taxibus to collect the traveller from her address and drop her off at the appropriate Underground station, where she will catch a train into London.
CAN THE TAXIBUS SAVE THE PLANET?
Although global warming studies are controversial, most predict that man-made emissions of greenhouse gases such as carbon dioxide will cause an increase in average global temperatures, and this in turn will precipitate more extreme weather phenomena such as flash flooding and hurricanes.
Transportation is a major source of greenhouse gases, accounting for as much as 33% of a nation's carbon dioxide emissions. What impact can IGT have in cutting this greenhouse gas output?
The taxibus has great potential for reducing greenhouse gas emissions. To elucidate this potential, let us again take Greater London as our example. Assuming that the average taxibus holds 8 passengers during the rush hours, and given that the typical occupancy of a car is 1.4 travellers, this equates to each taxibus vehicle having the capability of removing about 6 cars from the road (since 8 ÷ 1.4 is roughly 6).
This analysis thus suggests that in major cities, for every 10 thousand taxibus vehicles introduced, up to 60 thousand cars can be removed from the roads - if car drivers can be persuaded to travel by taxibus. In terms of greenhouse gases, this equates to 60 thousand carbon dioxide emitting engines being reduced to just 10 thousand (or reduced to zero if the taxibuses are powered by hydrogen fuel). There are around a quarter of a million vehicles on the roads at any one time in Greater London, the majority of these are private cars; therefore, introducing a modest fleet of just 20 thousand taxibus vehicles could in theory remove 100 thousand private cars from London's roads - this roughly translates to a twofold reduction in road traffic. By doubling the size of this taxibus fleet, an incredible fourfold reduction in traffic can be achieved. Would this traffic reduction manifest in reality, though?
Turning theory into reality means enticing car drivers to leave their cars at home and travel by taxibus. Considerable efforts should be made to make taxibus travel as attractive as possible in order to seduce people away from their cars. However, should global warming, air pollution and traffic congestion start to become really critical problems, then more coercive means of getting car drivers to switch to the taxibus may be necessary. Such means may include running persuasive advertising campaigns, increasing road and fuel tax, providing corporate tax incentives for companies that champion taxibus usage, and so forth. It is believed that once the public have got into the habit of travelling by taxibus, the car will be considered as a little bit clumsy. Eventually no-one will want to return to their old driving habits, especially when they see how traffic-free the roads have become.
Note: introducing a taxibus fleet might initially increase the number of vehicles on the roads, because to start with, the taxibus may attract bus passengers rather than car drivers (the taxibus being viewed as a superior type of bus) and since taxibuses generally have smaller passenger capacities than buses, there may be a net increase in vehicles on the roads. However, even if the taxibus fleet were to entirely replace the bus service, this net increase in vehicles would be small: each day in Greater London there are 4 million passenger journeys provided by a fleet of 6 thousand buses; in order to accommodate these bus passengers a fleet of around 10 thousand taxibus vehicles would be necessary, equating to a net increase of 4 thousand vehicles. This is an insignificant number compared to the quarter million or so vehicles on the roads in Greater London at any one time; and once this surplus of 'converts' from buses and other public transport are accommodated, the taxibus fleet can begin its job of cutting the number of cars on the roads.
Altogether, it is believed that the taxibus, plus the car pooling configuration of IGT, will have tremendous impact in cutting carbon dioxide emissions, especially if IGT is implemented in thousands of cities around the world.
Indeed, world-wide implementation is the ultimate goal for IGT, and this prospect is much more feasible than one might initially think. Though IGT comprises a sophisticated transport system run by computer and communications technology, the beauty of this system is that all its intelligence and complexity is contained within the controlling computer software rather than in transportation hardware. Compared to the complex and costly physical infrastructures of railway and underground railway transport networks, for example, the physical infrastructure and hardware of IGT is very basic: it comprises just vehicles and roads.
Since the nucleus of IGT is data-processing, once the software is written, it becomes easy to implement around the world. Most countries already have the required cellular networks, and all countries are covered by satellite electronic positioning. With these infrastructures already in place, the computer software that runs IGT can be installed virtually anywhere. In developing countries, even old and existing transport vehicles can be used as taxibuses, just by fixing an inexpensive communicator device on the dashboard in front of the driver. IGT is therefore very 'third world friendly' and will operate with equal efficacy in London or Mexico City. Indeed the developing world's heavily polluted and traffic congested cities stand to benefit the most from IGT.
Once the initial writing of the software that runs IGT is complete, IGT can become the global solution to traffic congestion, parking congestion, noise pollution, toxic air pollution and climate instability; IGT will provide reliable rapid transport, improved business efficiency, better health, and a greatly enriched quality of life around the world.
THE INTELLIGENT GROUPING MODULE
The intelligent grouping module is really the operational nucleus of IGT.
What follows is a general and somewhat intuitively-pitched description of certain desirable features that the intelligent grouping module might incorporate, and how this intelligent grouping module might handle certain important specific situations.
First of all, it must be understood that the intelligent grouping module will be performing an enormous amount of computational work during the normal operation of IGT. Consequently, it is crucially important to ensure that the mathematical programming of the intelligent grouping module is as computationally efficient as possible. In particular, the intelligent grouping module should be able to make rough estimates of itinerary compatibility with minimal computational effort: such an ability will enable the intelligent grouping module to rapidly scan for good itinerary matches, and only when a few good matches have been found would a more accurate itinerary compatibility calculation be applied to these good matches, in order to arrive at a precise Compatibility Index value, and in order to devise optimal transit routes.
The intelligent grouping module always seeks to produce the best intelligent grouping possible, ideally finding a transit vehicle that can incorporate a traveller's itinerary without adding any extra time costs whatsoever to the itineraries of the other travellers aboard. This ideal solution will often be possible: as anyone who drives a car knows, between any two locations there are usually several alternative routes that are more or less equally time efficient. Thus when faced with a new traveller journey request, the intelligent grouping module will first check if there are any transit vehicles that can accommodate the traveller simply by switching the vehicle to an alternative route; such a transit vehicle could convey the new traveller without incurring any delay to the journeys of existing on-board travellers.
This is the ideal case: new travellers are accommodated by an intelligent choice of route, and no time is wasted. However this perfect situation will not always present itself, and in general there will be a time cost for picking up and transporting new passengers. The intelligent grouping module decides whether this extra time cost is acceptable or not, and this decision, though handled automatically, is carefully weighed up. A huge diversion with a large time cost to pick up just one single passenger must be balanced by the inconvenience caused to the other travellers already on board the transit vehicle. The intelligent grouping module will need to be carefully fine-tuned in order to get this balance right, so as to maximise overall transportation efficiency.
The overall performance of the transit vehicle fleet is a key consideration: balancing the demands of routing efficiency against the need to pack as many travellers as possible into each transit vehicle. It must be understood that these two different demands can be in conflict, but may also be in harmony. The intelligent grouping module aims for harmony: it tries to place travellers with highly compatible itineraries into the same transit vehicle, so that good routing speed and efficiency are attained, even though many travellers are simultaneously transported. Itinerary compatibility typically occurs when the embarkation and disembarkation points for all travellers are reasonably aligned on a direct path, thus satisfying both the need for routing efficiency and the need to convey a sufficient quantity of travellers. Though complete accord between these two requirements will not always be possible, the intelligent grouping module always aims to achieve it.
When good accord between routing efficiency and passenger packing cannot be attained, the focus shifts to striking a balance between these two demands. This compromise will need to be carefully weighed up. It is important not to pack on too many travellers, as this may result in an excessively high value for the Compatibility Index of the transit vehicle, and a value greater than say 1.6 will not make these travellers very happy because their journeys will be quite elongated. If a new passenger would increase a transit vehicle's Compatibility Index to an unacceptably high value, then it may be better to place that passenger on another transit vehicle, if possible. On the other hand, it is important not to leave a passenger stranded: if there is only one transit vehicle currently in the vicinity of a new passenger, even though that transit vehicle would need to run a significant diversion to pick him up, it may be necessary to thus divert the vehicle in order not to leave this passenger waiting an unacceptably long time before the next suitable transit vehicle arrives. These sorts of situations will typically occur in the small hours of the night, or in smaller towns or rural areas, where there may not be so many transit vehicles available. During the day, and in major cities, there will be numerous transit vehicles, and the intelligent grouping module will rarely need to be concerned with keeping a passenger waiting.
As well as the routing efficiency and passenger packing balance, there is another important balance that the intelligent grouping module must always take into consideration: that between routing efficiency and vehicle proximity. The intelligent grouping module aims to place new passengers in transit vehicles with the highest itinerary compatibility; however it also tries to find a transit vehicle that is in close proximity to the passenger, in order to have the transit vehicle arrive for pick up within three minutes of the passenger making the journey request. These two requirements may be in conflict. There may, for example, be a transit vehicle whose existing itinerary commitments can very easily accommodate the new passenger itinerary, but whose current location is six minutes away from the passenger; there may, however, be another transit vehicle whose itinerary commitments are not such a good match, but this vehicle is located just one minute away from the passenger. The intelligent grouping module must make a balanced choice between keeping the passenger waiting six minutes for the more compatible transit vehicle, or placing him on board a transit vehicle within one minute, and accepting the compromise in routing efficiency (and therefore journey time).
Another automatic yet balanced decision the intelligent grouping module must make is whether to convey a passenger on a single transit vehicle, or split a passenger's journey using two or more different transit vehicles.
There will be many other balances that the intelligent grouping module automatically takes into account. These various balances may have to be fined-tuned on a trial and error basis: adjusting a little, and observing the effect it has on overall transit vehicle fleet performance (this is where a computer simulation of the transit vehicle fleet becomes very useful).
Different routing techniques could be experimented with to see which best expedites the overall transportation process. For example, it is conceivable that the technique of location clustering might speed up certain journeys. Location clustering is the bunching of pick-up points and/or drop-off points within the same small area. This might work well for suburban commuting, where a transit vehicle will pick up passengers from a cluster of homes in a particular suburban region, run all the way into the centre of town on a main road without stopping, and deliver these passengers directly to their various places of work, these places again clustered in the same locale.
Another technique relates to travellers that have identical pick-up or drop-off points: if these travellers also have compatible itineraries, placing them on the same transit vehicle can further increase transit vehicle efficiency, because the vehicle will have less individual pick-up or drop-off points on its route.
For the best results in calculating optimal transit routes, the intelligent grouping module must take into account not only the distance along a route, but also the the speed at which a transit vehicle can traverse the various roads that comprise the route. Although such a traffic-speed travel-time metric is more complicated to calculate, it yields many advantages. The complications come from the need to estimate the speed at which a transit vehicle can travel on each road.
A simple approach to estimating these speeds assumes that the transit vehicle will travel at the speed limit of each road traversed. Another simple approach - which would work quite well in traffic congested cities - assumes that on all roads, the transit vehicle will travel at the average traffic speed for that time of day (for example average traffic speeds in suburban London are around 20 mph for most of the day). A more sophisticated approach assumes the transit vehicle travels at the average traffic speed of each particular road, for the particular time of day, these average traffic speeds being calculated from previously recorded electronic positioning data received from transit vehicles in the fleet.
The most refined approach would use real-time electronic positioning data received from the transit vehicles fleet to provide an up-to-the-moment analysis of the current traffic speeds on all roads. This last approach is the one recommended, not only because it provides the most accurate estimate of traffic speeds, but more importantly, because it allows the intelligent grouping module to automatically take any traffic jams into account when devising optimal transit routes: if the current estimated traffic speed on a particular road is very slow, then the intelligent grouping module would, by the definition of the optimal transit route, tend to avoid routing transit vehicles via that road until the traffic situation improves. This means that the transit vehicles of IGT will tend to pre-emptively avoid traffic jams.
Note that once the intelligent grouping module has grouped travellers in a transit vehicle and has devised a optimal transit route for that vehicle, the task of directing the transit vehicle driver along that route is delegated to the electronic street navigation module, which operates in a similar fashion to in-car satellite navigation systems that are familiar to many drivers. With the electronic street navigation module in control, should the vehicle driver want to change course slightly (in order to avoid a small traffic jam for example), or should the driver simply make a routing mistake, the electronic street navigation module will adapt to, and continue from, his new position and circumstances (such adaptability and flexibility is one of the useful features of in-car satellite navigation systems, as any driver that has used one knows).
However should there be, for whatever reason, a large change in circumstances such that the transit vehicle gets significantly displaced from the original optimal transit route, then, with respect to this transit vehicle's displaced current position, the original optimal transit route may no longer be the most efficient way of transporting the transit vehicle's passengers. So rather than letting the electronic street navigation module try to adapt to the highly displaced position, instead, the intelligent grouping module will momentarily step in to re-optimise the transit vehicle's route. After the intelligent grouping module has devised a new optimal transit route for the vehicle, based on its displaced position, the electronic street navigation module will proceed as normal, directing the transit vehicle along that new optimal transit route.
This route re-optimisation would be set to kick-in automatically whenever a transit vehicle becomes significantly displaced from its intended route. Thus, provided a transit vehicle keeps close to the optimal transit route originally devised by the intelligent grouping module, transit vehicle navigation will remain under control of the electronic street navigation module; but should a transit vehicle, for whatever reason, significantly deviate from this optimal transit route, this will trigger the intelligent grouping module to step in and re-optimise that transit vehicle's route.
Such re-optimisation may mean, for example, that the transit vehicle will be given a new path to follow, and may also mean that it will be instructed to pick up and drop off its passengers in a different sequence. Re-optimisation might also entail that one or more passenger pick-ups planned for that transit vehicle are now cancelled, with those waiting passengers now collected by another transit vehicle, the intelligent grouping module having calculated that, under the present circumstances, this is the most efficient way to convey them.
Re-optimisation would also be set to trigger in other significant circumstances, such as when a transit vehicle gets delayed for a long time due to heavy traffic, or when the traffic congestion conditions have significantly deteriorated ahead along the current optimal transit route of the transit vehicle, now making that route less than optimal.
This complex juggling of circumstances is performed automatically in order to maximise the overall speed and efficiency of the transit vehicle fleet; transit vehicle drivers themselves are not involved (or aware of) this process. It is the controlling computer system that sweats; the transit vehicle drivers merely follow the resulting navigational instructions shown on their vehicle communicator device.
In summary: this section has considered some desirable features that the intelligent grouping module might have. However this is not an exhaustive survey, and further performance-enhancing features may be added. The beauty of IGT is that when performance improvements are made to the intelligent grouping module, these instantly alter the operation of the whole transit vehicle fleet. It is anticipated that the mathematical operation of the intelligent grouping module will be perfected over a period of many years. Each city in the world that implements IGT can employ mathematicians and software engineers to try to further increase the transportation efficiency of the intelligent grouping module: the great virtue of IGT is that any new performance-enhancing features devised can be easily implemented in other cities, just as a software upgrade.
QUASI DOOR-TO-DOOR TAXIBUS
Traditional public transport generally has its access points on main streets in the form of train stations and bus stops. However the taxibus is a unique form of mass transport which distributes its passenger pick-up and drop-off points more widely across smaller roads and residential areas as well as on main streets. This strategy, it is believed, will provide improved transportation efficiency, even if some time is lost by taxibus vehicle excursions into the back-streets.
We present here some variations on this strategy that may help further streamline taxibus travel.
The taxibus conveys passengers on a door-to-door or point-to-point basis, and so a certain portion of its journey will be spent in excursions into residential or other back-street areas to pick up or drop off passengers. The intelligent grouping module always tries to streamline these excursions so that any diversion into the back-streets to pick up or drop off a passenger can also act as a short-cut or cut-through on the overall taxibus route. However, not all back-street excursions can be made to double up as short cuts, and some excursions will slow down the taxibus journey.
One way to eliminate this slow down, and to further streamline overall transportation efficiency, is by confining all taxibus routing to main roads and larger streets (just as with regular buses), with passenger drop-offs and pick-ups taking place exclusively on these main roads. This confinement to larger streets would be controlled by the intelligent grouping module, which would create optimal transit routes that avoided the back-streets. This quasi door-to-door taxibus is considerably more convenient and flexible than a regular bus service because it still allows complete customisation of travel route according to each passenger's personal itinerary; each main street would have several taxibus stops containing a kiosk communicator device into which passengers can enter their journey request, and at which they can wait for their requested taxibus to arrive; it just means that passengers must walk to a taxibus stop on the nearest main road to catch a taxibus, and on disembarkation, it means that passengers will typically need to walk the last few hundred metres to their destination. One clear advantage of such taxibus stops is that, with passengers congregated in the street at such points, the taxibus will perform less individual passenger pick-ups and drop offs, as there will tend to be several passengers boarding and alighting together. This will speed up the taxibus since there will be a reduced number of passenger stops en route. Furthermore, by tending to pick up passengers in such batches, it becomes feasible (and necessary) to use larger capacity taxibus vehicles, thus further increasing the fleet efficiency.
A hybrid between the quasi taxibus and the true taxibus service is also conceptually possible, and is indeed an excellent compromise between efficiency of the former and the convenience of the latter. In this hybrid system, the taxibus picks up passengers directly from their current location (such as the home or office) as usual, but drops off passengers on main streets, so that passengers may need to walk the final few hundred metres to their destination. This sensible compromise will be especially useful near one-way systems and cul-de-sacs, where a taxibus might otherwise have to make a large diversion in order to deliver a single passenger. Indeed this hybrid system might advantageously be set to operate only at such awkward destinations as one-way systems and cul-de-sacs.
PASSENGER FARE METERING
Taxibus and car pool travel can be further streamlined by arranging for the controlling computer system to automatically calculate and levy the fare charge as passengers enter the vehicle. This means that neither passenger nor vehicle driver need be concerned with handling cash, issuing tickets or checking travel passes, thus facilitating rapid boarding of the transit vehicle, and making taxibus and car pool travel delightfully simple. For car pooling in particular, automatic fare charging is highly desirable, since the driver of a private car is unlikely to want to fumble around with coins and change.
A system of automatic fare charging requires some means of calculating and levying the fare, and there are several ways that the controlling computer system can do this. The simplest way uses data from the passenger's original journey request. This journey request includes all the relevant details: embarkation and destination points, the number of passengers travelling, and the amount of luggage carried. With this data, the controlling computer system can calculate the exact fare cost of the passenger's journey based on the distance between his embarkation and destination points, and charge this fare to the passenger's system-administered monetary account.
On its own, however, this system of calculating and levying fares is not foolproof: it is based on the passenger's journey request, but there needs to be some method of verifying that the passenger was actually picked up and conveyed in accordance with this request before the charge is levied on the passenger. This is particularly necessary in car pooling, otherwise a car pool driver could accept a passenger journey request, automatically receive payment for providing carriage, but not actually bother to pick up and deliver his passenger.
In car pooling, perhaps the easiest way of verifying that an accepted journey request has actually been carried out is by examining the electronic positioning data coming from the communicator device in the car pool vehicle. Using this data, the controlling computer system can determine whether the car pool vehicle did indeed travel to the passenger pick-up point and did indeed travel to the passenger destination point. This is ample evidence for verification. Remember: there is not much scope for dishonesty in this system since all drivers are registered on the controlling computer system, and should a driver engage in unreliable or deceitful practices, his passengers' complaints would rapidly expose him, and he would be banned from using the transportation system of IGT.
In taxibus travel, the concern is not so much whether the taxibus arrives to pick up the passenger, but whether at the pick-up point, some person other than the passenger climbs aboard, either in an attempt to gain a free ride, or simply just in error, and the taxibus departs with the actual fare-paying passenger left behind. However if this does happen, the passenger that was left behind can contact a human operator at the control centre of IGT and explain the situation: this operator would hastily arrange for another taxibus to pick up the stranded passenger, and the operator would also contact the driver of the first taxibus vehicle and ask him to investigate what has happened.
Another concern is that a group of passengers travelling together might try to enter a taxibus, when only one passenger is specified on the journey request, in order that the other members of the group can avoid paying for their travel. However, this situation should easily be spotted by the taxibus driver, whose is responsible for ensuring that the correct number of passengers board (and alight) the taxibus at any stop point.
A more robust method of verifying that the correct passengers have boarded a taxibus (or car pool) vehicle would employ the smart card technology. With such technology, the passenger would keep his personal smart card in his wallet or purse, and this card would be remotely scanned by a card reader in the vehicle communicator device as the passenger boards, thus confirming a correct pick-up, and therefore verifying that the fare charge could be levied on the passenger.
Another means of verifying passenger pick-up is possible when the passenger carries a cellular telephone or wireless PDA communicator device: it is quite feasible for this phone or PDA to automatically exchange data with the transit vehicle communicator device to establish that the passenger has boarded. This data exchange could be facilitated by an infrared or a short-range wireless data link (many cellular telephones and wireless PDAs have infrared or short-range wireless data link capabilities). This method of verification may not always work, however, because passengers may have their phones turned off, or their phones may have run out of battery power.
Automatic fare calculation can even be applied when a taxibus is hailed in the street: passengers that manually hail a taxibus will specify their journey request at an on-board kiosk communicator device located inside the taxibus vehicle; if the passenger is a registered user, his system-administered monetary account will be debited in the normal way; if the passenger is not a registered user of IGT, he will specify his journey request at the on-board kiosk, and pay for the trip by swiping his credit or banker's card at this kiosk.
GROUPS OF PASSENGERS
Group travel by taxibus or car pool is very straightforward when each person in the group is a registered user and carries his or her own communicator device: each person simply makes an individual journey request to the same destination at more or less the same time. On receiving these multiple requests arising from the same geographic location, the controlling computer system will automatically try to place these people on board the same transit vehicle or vehicles - simply because that is the most efficient way to transport them.
Another way that a group of registered users can travel is by nominating a group leader: all members of the group must enter the user name of the leader into their communicator devices to inform the controlling computer system that they are members of one group, and that their leader is the user specified. Should some group members not have communicator devices, this does not present a problem, since these people can borrow a communicator device from one of their fellow travellers, log into their own system account by entering their user name and password, and then, like everybody else, enter the user name of the group leader. Once the group is thus defined to the controlling computer system, the leader can enter a single journey request for the group, and the controlling computer system will send a transit vehicle to transport the whole ensemble.
Group travel can be arranged more simply by one user making a journey request which includes details of the number of passenger seats required. On receiving such a request, the controlling computer system will send a taxibus vehicle with sufficient capacity to transport this number of people. The controlling computer system will charge the entire group fare to the user who made the journey request, and thus this user may need to be reimbursed by the group. This method of group travel, however, introduces a security breach: when several passengers travel under one user's system account, although the identity of this user will be known to the controlling computer system, the identities of the other passengers will not. Car pool drivers that are concerned with security may prefer to avoid groups travelling under one system account.
Another form of group travel occurs when one passenger orders a taxibus journey to a specified destination, but would like his taxibus vehicle pick up a friend on the way, so that they can travel together to the same destination. It would be possible to include this sort of group travel option (but note that it would only be available to a passenger when the friend's address is located more or less on the way to the destination - the controlling computer system would reject the request otherwise). Of course this sort of group travel is more simply achieved by first taking a taxibus to the friend's address, alighting, and subsequently ordering a second taxibus to convey both travellers to the desired destination.
In general, group travel is a very efficient use of the taxibus: groups tend to board or alight together, which means that the transit vehicle has less pick-up and drop-off points on its route to slow it down.
REGISTERING WITH THE SYSTEM
To apply to become a registered user on the files of the controlling computer system and thus gain access to taxibus and car pool travel, some personal details must first be provided, such as the applicant's name, date of birth, sex, home address, driver's licence number, telephone number, email address, occupation, banking and credit details. For security reasons, this data will be validated to ensure that the details are correct. Once validated, the applicant will be set up with a system account (which includes a system-administered monetary account), and a user name and password that enables him or her to access this system account, and to make use of all the transport facilities of IGT. Users would usually need to transfer funds to their system-administered monetary account before they can travel as a passenger.
As well as travelling as a passenger in taxibus and car pool vehicles, the same system account will also allow the registered user to act as a car pool driver.
Note that since a registered user's system account incorporates a monetary account within it, there are certain security considerations that must be fully examined. Although the user name and password scheme just mentioned is reasonably secure, it may be deemed necessary to include additional security measures such as issuing each user with a unique smart card which is automatically read by the transit vehicle communicator device when the user begins a journey, and thus automatically identifies the passenger to the controlling computer system. Smart cards would also be helpful at roadside kiosk communicator devices: the smart card could be read by the kiosk, thus identifying the user to the controlling computer system without him needing to enter his user name.
SECURITY IN TAXIBUS TRAVEL
The electronic navigation taxibus is probably the safest means of public transport ever devised, offering more personal security than even the private car. This is because it provides a door-to-door service overseen by a professional driver, and because all details of all taxibus journeys are logged on the controlling computer system. These details include the identities of the driver and all fellow passengers, the exact route traversed by the taxibus, the place and time each passenger boarded and alighted, and for extra safety, video surveillance inside the taxibus.
In addition, the controlling computer system will keep a security file for each registered user. Any reported incidents of anti-social behaviour will be recorded on the user's file, and if any particular user is implicated too frequently in such incidents, he or she would be banned from using the transportation system of IGT for a certain number of months. Just the possibility of a ban should be an incentive to maintain proper personal conduct in the taxibus.
Some passengers may be a little worried by that fact that the taxibus (and a car pool vehicle) drops them off right outside their house, thereby indicating to fellow travellers where they live. However, there is a simple solution for this concern about privacy: instead of specifying their exact home address as their travel destination, such passengers can specify an address which is say just a hundred metres away from their home, perhaps in front of a local shop or similar location. The controlling computer system would then automatically direct the taxibus to drop the passenger off at the specified point.
PICK-UP DELAY FINE
Passengers who make a journey request for a car pool or taxibus vehicle, but who are not ready to leave when the vehicle arrives, will automatically be charged a small fine for every minute that they keep the transit vehicle waiting. The controlling computer system will know when the transit vehicle has arrived at the passenger pick-up point from the incoming electronic positioning data it receives from the communicator device on the vehicle. Once the vehicle arrives at the passenger's pick-up point, the controlling computer system begins the delay-charge timer. Any delay in boarding that is longer than one minute will incur a fine, levied on that passenger's monetary account (the controlling computer system will make the car pool driver or taxibus operator the direct benefactor of this fine). This fine will gently encourage passengers to be prompt for pick-up. Pick-up delays not only inconvenience the driver and other passengers, but they also equate to a waiting transit vehicle in the road that may be partially blocking the thoroughfare. Should a taxibus or car pool vehicle arrive at the pick-up point and find that the passenger is still not ready to go even after waiting a few minutes for him, the controlling computer system will instruct the driver of the transit vehicle to leave without the passenger. That passenger will incur a fine equal to the minimum fare charge for travel in that transit vehicle, and will have to resubmit his journey request to the controlling computer system if he still requires transit. When a passenger frequently causes delays through his or her lack of punctuality, he or she may be barred from using taxibus and car pool transportation for a period of time.
Quick and efficient passenger pick-ups are important to the smooth functioning of IGT. The waiting passenger's communicator device will generally provide a countdown to the estimated time of arrival of his requested car pool or taxibus vehicle, so the passenger can have little excuse not to be ready.