§ 15. Mr. Longden
asked the Minister of Transport what has been the effect on the accident rate of the imposition 421 of speed limits of 40 and 50 miles per hour in built-up areas; and whether he will now make it compulsory for motorists in such areas to dip their headlights rather than rely only upon their side-lights.
§ Mr. Marples
From a sample survey in the London Traffic Area the Road Research Laboratory concluded that the imposition of a 40 m.p.h. speed limit on unrestricted roads reduced the number of personal injury accidents by 19 per cent. On roads previously subject to a 30 m.p.h. limit there was no significant change in the accident rate. No 50 m.p.h. speed limit has been imposed in built-up areas.
With regard to the second part of the Question, I am now studying a report which the Road Research Laboratory have recently completed on the dipped headlight experiment in Birmingham.