Why public transport can't work
Politicians and environmental campaigners would like everyone to make less use of their cars and to use public transport instead. Their sentiments are admirable but there is one enormous problem... None of the existing public transport systems can ever replace the automobile... "Oh but you're wrong!" I hear you cry. No, I'm not and I'll explain why.
The automobile and all of the existing public transport systems (including trains, trams, monorails, buses etc) are fundamentally different transport concepts.
The automobile is an individual transport technology, that is, it is designed to transport an individual from A to B. All of the existing public transport systems are group transport technologies, that is, they are designed to transport groups of people from A to B.
This may not sound like a big distinction but the consequences of this difference are huge;
A group transport vehicle must stop regularly at stations in order to allow passengers on and off, it cannot be avoided. If you reduce the number of stops then you also reduce a passengers access to transport and fewer people can use it. The consequence of frequent stops is that the average speed of the system is extremely poor indeed as the vehicle spends much of it's time accelerating, decelerating and stopped. The only way to improve the average speed and reduce the journey time is to prevent stops, having a vehicle which has a high top speed doesn't matter because each time it stops the time taken for the journey increases and the performance suffers.
A group transport vehicle cannot take you directly to where you want to go. By it's very nature the group vehicle can only take you approximately in the general direction you want to go. They have to provide an average destination approximately where most people would like to travel. The group transport vehicle must always follow a fixed route. This means that passengers always have to make additional journeys, they must travel to the station or stop and once they reach the route destination they again have to travel to their final destination by other means. Each additional change of route or vehicle imposes additional delays on the passenger and the performance suffers.
A group transport vehicle cannot be used on demand. Because passengers all wish to travel at slightly different times, the group vehicle must be run to a schedule. The number of vehicles on the schedule obviously depends on the probable occupancy, if few people wish to use it then scheduled vehicles will be few and far between meaning that passengers have to wait often for long periods until the next vehicle arrives. This also reduces the performance. If a route is popular then the schedule will be frequent and the wait will be less, but will still be there and the passengers may be required to stand, or even crush on to the vehicles.
A group vehicle must by it's nature be large and therefore heavy in order to carry large numbers of passengers. This size and weight impinges on the underlying infrastructure. In order to support a large and heavy vehicle, the underlying road or rail must be heavily engineered, this means that the vehicles themselves and the infrastructure to support them must be expensive and less than environmentally friendly. Indeed accelerating and decelerating a very large and very heavy vehicle comsumes a lot of energy, far more than a small vehicle meaning that group vehicles are only environmentally friendly when they have many occupants, such as during the rush hours. At off peak times when they are almost empty they are very enviromentally unfriendly indeed.
These are fundamental failings of conventional public transport systems which cannot be overcome by any group transport vehicle. They are inherent in the system.
Cars obviously have their own problems with inefficiency, congestion, cost but they can never be replaced by group public transport systems because they are a fundamentally different concept... They are an individual transport technology.
I put it to you that spending billions of pounds and effort lobbying to replace the car with conventional public transport systems is a futile exercise, the overwhelming majority of journeys will continue to be made using the car until there is a credible alternative which can replace most of the features the car has; On demand 24 hours per day, fast door to door service without the need to know routes or worry about schedules. And this can never be accomplished by conventional public transport.
The solution to replacing the car is to develop a public transport system which makes use of individual vehicles, and not group vehicles. Fortunately, transport researchers have been developing exactly this kind of mass transit system over the last 40 years. It is called Personal Rapid Transit (PRT).
There are a couple of companies started by transport researchers trying to produce working PRT systems. The largest American company is Taxi 2000, their system is called Skyweb Express. The most developed UK PRT system is called ULTra, developed from a University of Bristol spinoff company called Advanced Transport Systems Ltd.
Only one of these systems, or other PRT implementation very much like them can make a significant dent in car usage. Trains, buses, monorails, trams simply cannot make a useful contribution.