The Government is committed to introducing tolls by 1998 but is insisting on a hi-tech system, as opposed to toll booths or paper disc-based systems.
Mr Watts said 29 consortia, involving 70 firms, had expressed an interest in designing a system. The three or four best systems will be selected early next year for extensive trials, using a real section of motorway and an experimental testing ground. In January 1996, the Department of Transport will not select 'a winner' but will draw up a specification for the system based on whichever technology performed best in the trials. Then the contract will be put out for tender again.
The prize for the eventual winner is huge. Most of the country's 24 million vehicles and probably - depending on the type of system chosen - the 2,000 miles of motorway network would have to be fitted with the technology.
But the department has been criticised over its running of the competition because the company developing the best system will not necessarily be offered the contract. One bidder said: 'They are expecting us to do all the research in developing a system and then some other company could come along and rip off our ideas.' Mr Watts defended the Government's approach saying: 'The private sector are always trying to get the taxpayer to pay for its research. There are clearly a lot of companies interested.'
The Government says it could raise pounds 700m a year through motorway tolling if cars were charged 1.5p per mile and lorries 4.5p. However, the Labour Party is currently opposed to road tolling and the scheme may be scrapped after the next election.
Nearly all the systems make use of smartcards. This involves every car using the motorways being fitted with a device into which a card is inserted. The driver will have prepaid for the journey by 'charging' the card at a vending machine and the toll will be deducted automatically.
Broadly, there are two main types of system with a number of variants. All but three of the systems use some kind of communication system - microwave, infra-red or laser - between the vehicle and roadside beacons. Most of these require two-way communication and need to be backed by an enforcement system using video cameras which will take pictures of cars that are not complying with the regulations.
Some simpler systems rely on visual means of enforcement through a display panel on the windscreen and communication needs to be only from the beacons to the car.
The second type of system, put forward by three of the consortia, is based on the network of satellites used by the US military, called Global Positioning Satellite, which enable a vehicle to be located within a few metres. The car's on-board unit can then be programmed to deduct charges from the smartcard each time the vehicle passes certain points, such as motorway junctions.
The advantage of a satellite- based system is that it does not require such sophisticated roadside technology but at present the cost of installing a GPS system on a car is prohibitively expensive. It will also need to be backed up with a communication system with a control centre, through the mobile telephone network, so that the information in the car's unit can be updated.
The Department of Transport hopes that the selected system could be used to operate an urban road-pricing system, although the Government is not committed to that policy yet.
While the technology is being developed, the political battle over road tolling remains to be fought. Last month, the all-party Commons transport committee said that motorway tolling would divert cars onto minor roads and would be environmentally damaging. Instead, it suggested higher fuel taxes.Reuse content