Britain yesterday unveiled a controversial plan to test electronic road tolls on motorways as part of a long-term attempt to curb car usage. The 12-month pilot programme begins early next year and targets two major motorways - one near Edinburgh in Scotland and another leading to Leeds in England, officials said. Drivers involved in the programme will have their vehicles fitted with electronic devices that are automatically charged by roadside computers every time they use the motorway. But no money will actually change hands during the trials.