Public Transit in the Dualmode Era: Introducing a Public Transit Revolution


Kim Goltermann

Reading through the numerous dualmode transportation proposals presented on the Internet it is obvious that most of them calculate with some sort of public transit service utilizing the guideways, so that the transportation poor can also enjoy some degree of mobility in the dualmode era. How this mobility is going to come about is however only very vaguely described. Not many developers have bothered to describe in any detail the kind of public transport services they intend to include with their concepts, and the impression is that public transportation in the days of dualmode will be similar to present services just running on the guideways without chauffeurs.

In fact, the only one I could find that beg to make a difference, offering detailed information about the public transit services planned, is the RUF concept by Palle R. Jensen. The RUF concept essentially proposes a dial-a-ride service using dualmode mini-busses that will utilize guideways for part of their trip. Readers are encouraged to visit the RUF homepage for a more detailed description of the services envisioned. Although the RUF dial-a-ride service (if workable) will certainly improve public transit, it fails to promise the true on-demand door-to-door affordable service that could really propel public transit into the 21st century.

The failure of dualmode developers to offer door-to-door connection to public transit users must surely be due to lack of imagination, as new technology in conjunction with a dualmode guideway network provide ample opportunity to improve on today’s measly public transport services. It might even be possible to design a public transit system that could compete with the private automobile for convenience and comfort.

The purpose of this paper is not to recount the many insufficiencies of conventional public transportation, so I will make it short: Public transport offer inferior services and they are expensive to run! The only form of public transport that offers convenience and comfort to its users are taxis, and they are too expensive. Unfortunately experiments have so far revealed that dial-a-ride services (like the RUF proposal) are almost as expensive as taxis when costs per passenger per mile are compared. So what are our options?

It is a sure bet that for any road-bound vehicle the chauffeur will be the largest single cost contributor, and if one could eliminate the need for paid chauffeurs much would be gained. For trains the reverse will be true. Chauffeurs are a minor liability while capitalization and maintenance of the purpose built rails (guideways) contribute most of the cost. Thus, the challenge is to devise a system that 1) offers services equal to the privately owned automobile, 2) doesn’t require purpose-built rights-of-way or other expensive infrastructure and 3) reduces to an absolute minimum the need for paid chauffeurs, taking advantage of patrons own driving-skills whenever possible.

If PRT principles (uninterrupted origin-to-destination, no schedules, privacy) were adopted, the transport service would in many ways resemble the service provided by a private car, but the attractive door-to-door service would of course be unattainable if the PRT vehicles were restricted to the guideways. Passengers would have to walk to the nearest PRT station, and again at the other end from a PRT station to their exact destination.

The obvious solution is to give public PRT vehicles dualmode capability, so they can provide door-to-door connection. This will undoubtedly give much improved service and might even entice a few car owners to give up their cars and use public transit instead. The only real problem with this solution is that those who depend on public transit are often also those unable to drive a car. A dualmode PRT vehicle would only be available to those in possession of a driver license and therefore wouldn’t qualify as a genuine public transit service. Which bring us back to square one!

In this proposal for an improved public transport service it is assumed that a dualmode guideway network covering a major metropolitan area with numerous access-points has already been built primarily for the convenience of privately owned vehicles. In such case will it add very little extra cost to accommodate public vehicles as well. It is not specified if the system will be true dualmode or pallet operating, nor if it will utilize MagLev, LSM, steel wheels, rubber tires or some other principle, as these considerations are irrelevant in the context of this commentary.

The guideway network will enable public vehicles to provide automated transit throughout the city, and if small vehicles seating only 3-4 people are used, it will also be possible to offer public transit users the same privacy and security as experienced in a private car. The door-to-door service is harder to come by, but maybe the answer will be provided by a technology developed for a slightly different purpose.

In France INRIA (Institut National de Recherche en Informatique et en Automatique) has developed the CyCab; a small versatile vehicle that can be driven either manually (via a joystick) or tele-operated (via an on-board camera). Intended for historic city centres, university campuses and other zones with limited access to regular automobiles, this small electric vehicle can transport 2 people with 30 km/hour anywhere even if users have no driving skills of their own.

Interesting as this concept is, it nevertheless has limited speed, range and coverage and is suitable for special transportation situations only. However if we apply the technologies developed for CyCab to a dualmode PRT vehicle instead, we could create a near perfect public transit system. A quantum leap in public transportation service with the following characteristics:

- PRT vehicles can drive in the streets with no one behind the steering wheel, as chauffeurs (operators) from a remote location control them. It would be possible for a chauffeur (operator) to shift his attention immediately from one vehicle to another, usually only assisting each vehicle for a few minutes. This kind of service would be the most expensive because of the involvement of a chauffeur.

- It will also be an option for users to control the PRT vehicle themselves. While in street-mode a passenger would take the role of driver, and this will be the most common way to utilize the system, as the majority of a population have driving skills of their own. This service will be intermediately priced.

- Finally will it be possible to use the vehicles in an automated fashion on the guideways. This will be used for the middle part of longer intraurban trips, and a trip could even be entirely on the guideways as there will be special PRT stations, especially in the centre of a city, where the vehicles can be accessed. Using the guideways will be the cheapest option available to public transit users.

The vehicles of the system will be very easy to operate, being restricted to maybe 50 km/hour in the street-mode for safety reasons. In fact they will be so easy to use that even old people that gave up their car or teenagers down to 14-15 years of age could drive them safely. These groups could be restricted to speeds of only 25 or 30 km/hour while in street-mode. Who should be allowed to drive these vehicles is of cause a political decision, but if the vast majority was allowed behind the steering wheel only few people would be dependent on paid chauffeurs (operators) for door-to-door mobility, and as velocity in street-mode would be very low, there would be few safety concerns.

One of the few disadvantages of this system, common to all PRT systems, taxis as well as private cars, is that users pay for services on a "per vehicle" basis rather than on a "per seat" basis. This will make transit more expensive for patrons going alone, as they will have to pay for a number of seats not used. Although most people have demonstrated their willingness to pay what it takes (buying cars), there will always be a group of people unwilling or unable to pay on a "per vehicle" basis. These people can be helped with a "share-a-vehicle" Internet service connecting people with identical transportation needs in terms of origin, destination and time.

When only 2-3 people are needed to share a vehicle, thus reducing the price for each person, it will almost always be possible to find someone having approximately the same transportation needs. And sharing a vehicle with one or two strangers will be an acceptable option for those trying to keep spending down, especially considering that –

- The trip will be door-to-door or very near so.

- The identity of all travel companions will be known, as all users are registered.

- The vehicle will be public, so no one needs to invite strangers into their precious private cars.

- Everyone pays their share of the fare, being billed separately according to a fixed formula, so no disagreement on payment can occur between users.

This comment doesn’t leave space for a detailed description of the many aspects of the system (some aspects haven’t even been worked out), but as everyone will have access to the Internet in a few years time (through PCs, phones or other communication devices) this service will be available to everyone.

The following description of an imaginary trip will give an impression of how versatile a public transit system we could build if we set our minds to it. The problem in this example is to get from one end of the city to the other for a party. On our way will we need to buy something for the hosting couple and after the party will we need to be helped safely back home again.

First step will be to obtain a vehicle for the trip, and this can be done in one of four ways. We can ask (by phone or via Internet) for a vehicle to be dispatched in the tele-operated mode to our front door, where it will arrive after a few minutes reserved for our use. We can also use the Internet to find out where in our neighbourhood there is a vacant vehicle parked, and we could even have it reserved for us. The reservation will cost us a small fee, but it would be cheaper than to have a vehicle sent to our front door. The third option is to simply find a parked vehicle somewhere in a nearby street. This will cost us nothing, but we will have to chance it. Finally we could walk to a nearby PRT station and obtain a vehicle already on the guideway.

Having obtained a vehicle we drive to a nearby florist’s using the streets as if we were driving a normal car. We opt to drive the vehicle ourselves, because it is a cheaper option than the tele-operated mode. At the florist’s we park the car at the kerb, but as we will need to continue the trip shortly we reserve it, so no one can claim it while we do our shopping. We could even leave our belongings in the car as only we have access to its interior. This reservation will again cost us a small fee depending on how long we reserve the car for.

Back from the florist’s with a nice bouquet, we continue our trip, again using street-mode as we head for the nearest entry point to the guideways. At the entry point we order the vehicle to be brought to an exit point near our final destination. While on the guideway we have a little time to relax, watch TV, surf on the Internet or whatever we choose, before we drive the last short distance from the guideway exit to the home of our hosts. Again we opt to drive ourselves trying to keep spending low.

After arriving on the doorstep of our hosts, relaxed and dry, we park the car in the street and it is now available for others to use. Or for the system management to dispatch in the tele-operated mode to wherever it is needed.

Much later in the evening we need to acquire another vehicle for the trip back home. This and everything else will be identical to our outbound trip except for one little difference. As everyone had too much of the good wine, no one will be able to drive. The street-mode parts of our homebound trip will therefore have to be tele-operated with a chauffeur (operator) controlling the vehicle from a remote facility. Safely home again we simply leave the vehicle in front of our house. All services received will be billed to our account or paid for with a pre-paid smart card.

One of the biggest advantages of the system proposed here is the very efficient use of chauffeurs (operators). Operators will only be needed if no one among the users of a vehicle is able to drive it, and if needed they will usually only have to assist each vehicle for a few minutes (to and from the guideway), being immediately reassigned to other vehicles when done with a job. Operators will work in the comfort and security of a large control facility or maybe even from their own home. Never will they be exposed to adverse weather, robberies, violent passengers or the dangers of traffic in general.

Efficient management of incoming requests for driver assistance mean that an operator is assigned to a job only seconds after the request is received. Computers will assign incoming jobs to the first available operator with priority given to requests from vehicles about to leave the guideways. As there are many operators working at any given moment, there will always be a handful operators in the process of completing their assignment thereby becoming available for new assignments.

Another advantage of tele-operated vehicles is the management's (computers, that is) ability to redistribute vehicles in order to balance supply and demand locally as well as overall. If a number of operators are not needed for incoming jobs for a while, they can be used to optimise the distribution of vehicles in the streets according to computer modeling of upcoming demand levels. Notice that only a small fraction of the PRT vehicles are stored at PRT stations during idle periods; the rest being parked in the streets.

Yet another beauty of this system is the possibility of catering for special needs within the general system architecture. Groups can order tele-operated mini-busses and people with disabilities can have vehicles capable of taking on wheelchairs at their disposal (advance booking required). As already described, sharing a vehicle is an option for those prioritising economy over convenience. It is even possible to allocate any transit subsidies in a personalized manner through the billing system. Reduced prices (or free services) can be offered to those with legitimate needs, instead of subsidies "en masse" to public transit in general, as is the case now.

It will undoubtedly demand a lot of ingenuity and development effort to create a system as described here, but I see no need for new discoveries. High capacity (wireless) tele-communication systems capable of transmitting live pictures at low prices are being started up all over the world as these lines are written. Everything needed has already been invented and demonstrated, and all we need is to combine the technologies to benefit from their symbiosis´.

All in all this description of a public transit system is, in most respects, the equal of the privately owned automobile, capable of providing convenient services at competitive prices. Just as an aside it could be mentioned that the combination of tele-operated dualmode vehicles and a guideway network would also totally revolutionize the transport and distribution of goods within the confines of a metropolitan area.


Last modified: September 26, 2000