asked the Secretary of State for Transport what research is being carried out, and with what results, into the movement of vehicles other than by the use of petrol.

The Department of Transport, through the Transport and Road Research Laboratory, has in progress, or has completed, a number of research projects concerned with the movement of vehicles other than by the use of petrol. These include research on novel and conventional electric trams and trolley buses; increased efficiency of diesel powered lorries; and the relative merits of petrol and diesel engined vehicles.Work is in progress, supported by the Department of Industry, to develop suitable batteries for road vehicles. There are also a number of trials of electric road vehicles taking place.In addition, joint research programmes with British Rail and London Transport include work on improved power systems for electric trains.Results obtained so far from work on electric road vehicles have indicated that these are not economic for general use in present circumstances, but much of the work is still in progress.