HC Deb 12 December 1996 vol 287 cc294-5W
Sir Roger Moate

To ask the Secretary of State for Transport how many road fatalities arising from the loss of road wheels from heavy commercial vehicles occurred in each of the last five years; how many wheel loss incidents there were; what research his Department has(a) commissioned and (b) evaluated into this matter; what assessment he has made of the advantages of safety wheel nuts in reducing accidents; and if he will make a statement. [8706]

Mr. Bowis

It is estimated that each year there are approximately five to six fatal road accidents involving heavy goods vehicles in which wheel detachment occurs. As data on the causation of accidents are not routinely collected by my Department, figures on the number of fatalities arising from such accidents are not available.

With regard to the number of incidents involving wheel loss each year the cases indicated by the analysis of the Vehicle Inspectorate database represent only those cases where the police have called upon an investigation to be carried out by the inspectorate.

My Department has been represented for many years on the British Standards Committee for wheels and tyres who commissioned research by the Motor Industry Research Association—MIRA—into the problems of wheel loss from commercial vehicles. This research complemented work carried out by the University of Exeter on behalf of the Institute of Road Transport Engineers—IRTE—and the Department of Trade and Industry which contributed some £35,000 to the funding.

Results of the MIRA research showed that the basic cause of the problem of wheel loss is a relaxation of the tension in the wheel fixing and that this took place regardless of whether the vehicle was moving. The British Standard code of practice for the selection and care of tyres and wheels for commercial vehicles advises that wheel fixings should be rechecked for tightness after the vehicle has been standing for 30 minutes or has travelled between 30 or 40 km. Our assessment of the engineering principle of proprietary safety wheel nuts is that they do not address the problem of this initial loss of tension of the wheel fixing and therefore do not reduce the need for regular maintenance.