Personal Rapid Transit (PRT) is a driverless public transport system for routes where demand is up to around 5,000 passengers an hour. It consists of small computer controlled pods that carry up to 4-6 passengers on dedicated and segregated track or guideways direct from origin to destination without stopping. The average operating speed is around 30mph, with all stops offline so following pods can overtake and not be delayed, so it is highly competitive with cars and around double the average speed of a bus. A well designed scheme will ensure that average waiting time at stops is no more than a minute. Infrastructure costs are far lower than for light rail systems and as drivers are not required the operation costs are also low.
A PRT route connecting Heathrow’s Terminal 5 with a business car park is presently undergoing trials. It will replace an existing shuttle bus and encourages users to pay premium parking rates in exchange for a fast, reliable connection. If the initial pilot route is a success the long term plan is to roll out the network to connect all terminals, car parks, businesses and transport hubs around Heathrow. The Heathrow scheme uses a British designed and manufactured system and is a good example of advanced green manufacturing which the government is seeking to support.
Work done by Colin Buchanan to study the potential for a PRT system in Daventry found it would prove far more effective than alternative modes of public transport such as buses in generating modal shift. Modelling undertaken by independent experts also confirmed that the system could not only cover its operating costs, but actually pay back the cost of the capital investment in the long term.
PRT offers a unique public transport opportunity in that it makes it possible to recover the initial capital investment through fare revenue. At the same time the system offers the opportunity to withdraw local bus services thus reducing subsidy spend by local authorities. The system is ideally suited to address areas where trips are dispersed as the network can be set up on a grid system that allows trips to take place between any two points on the network.
The main opportunities for introducing PRT would appear to be:
- In new towns where there is substantial space to introduce infrastructure around existing structures without negatively effecting the townscape;
- In campus type developments proving internal movement and connecting into key transport hubs;
- In areas where there are a high proportion of dispersed trips and conventional public transport would not be effective in increasing sustainable mode share.
PRT can be a low cost and British designed alternative to expensive public transport schemes and is worthy of consideration when examining transport solutions, for example the St Albans Abbey to Watford Junction line which is being converted to light rail might have provided the appropriate conditions for a PRT system.
There are downsides in that it would be difficult to retro-fit into existing built up locations.
So is PRT the new public transport system that will replace the bus or is it a fanciful idea that has no future?