John MacGregor, the Secretary of State for Transport, signalled the Government's determination to push ahead with the controversial proposal to charge all users of the 2,000-mile motorway network by announcing a tight programme of equipment trials.
Invitations are being sent to 375 companies, 90 per cent of them British, asking them to submit schemes for implementing tolling.
All 23 million cars will have to be fitted with a device to be read by roadside equipment at the 700 motorway junctions without vehicles slowing down. The equipment will also be used for congestion-charging in cities, although the Government is not yet committed to this, and will probably need to be compatible with European equipment.
The only method of payment will be electronic. Toll booths have already been ruled out, as has the idea of baskets into which cash can be thrown.
Companies will have until 31 May to respond. By the start of next year, the department expects to have a full-scale experiment running using the most promising designs and will choose one in 1996. Legislation will then be required to introduce tolling. It is not known whether car owners or government will pay for the on-board equipment, or what the scheme will cost.
However, Mr MacGregor yesterday reiterated an earlier suggestion that 1.5p per mile for cars and 4.5p for lorries would raise pounds 700m per year, a third of the cost of the annual new roads programme. The equipment needed to be sophisticated enough to ensure that peak-time users could be charged a premium rate.