§ Lord Braybrookeasked Her Majesty's Government:
Whether tests have been carried out on the braking and jack-knifing of 38-tonne lorries performing emergency stops at maximum braking from 60 mph in wet and dry conditions; and whether similar tests have been carried out on family cars stopping from 70 mph; and, if so, what were the stopping distances in each case.
§ The Minister of State, Department of Transport (Lord Brabazon of Tara)Recent tests on fully laden vehicles carried out by the Transport and Road Research Laboratory gave the following average stopping distances: heavy goods vehicles travelling at 60 kph took 30 metres to stop in dry conditions, and 32.4 in wet; cars travelling at 100 kph took 52.8 metres to stop in dry conditions, and 72.9 in wet. On the basis of these results, the stopping distances for heavy goods vehicles travelling at 60 mph would be approximately 77 metres in dry conditions, and 83 in wet; and cars travelling at 70 mph would take approximately 67 metres in dry conditions, and 92 in wet.