Heavy Vehicles (Speed) Rear-Admiral Beamish asked the Home Secretary whether, in the interests of the conservation of rubber and petrol, he will give instructions to the police force to prevent heavy vehicles on main roads, particularly in rural areas, from driving at speeds in excess of the legal limit? Mr. H. Morrison It is generally recognised that excessive speed, particularly by heavy vehicles, leads to a disproportionate wear of tyres and consumption of petrol, and I have already asked the police to do all they can to secure observance of the speed limits.