§ Mr. PawseyTo ask the Secretary of State for Transport what was the result of his Department's research into the incidence and causes of tyre failures among heavy goods vehicles on motorways.
§ Mr. Kenneth CarlisleA survey of tyre tread debris left by 157 tyres on the M4 motorway was carried out between June and October 1991. The debris consisted of 72–46 per cent.—new—first used—tyres and 84–54 per cent. retreads. Only one piece of debris was of unknown type.
Tyre failure by heavy goods vehicles on motorways is almost invariably the result of tyres overheating. This can be a consequence of overloading, under-inflation—or both—running under-inflated following a penetration or running for long periods at higher speeds than those for which the tyres were designed at their maximum load.
I have arranged for a copy of the Transport Research Laboratory's working paper—Ref.: WP/VS/222—to be placed in the Library.