HC Deb 29 October 1980 vol 991 c308W
Mr. Spearing

asked the Minister of Transport what were the broad categories of reasons given for the 6,339 immediate prohibitions issued by the licensing authorities in respect of heavy goods vehicles in the traffic year 1978–79.

Mr. Kenneth Clarke

These prohibition notices arose from checks carried out by this Department's vehicle examiners at the roadside and at operators' premises. Defects recorded on such notices are not analysed, but it seems likely that the main reasons will follow a similar pattern to those causing failure at the annual test. Apart from brake performance, which cannot always be assessed at the roadside, the most common causes of failure at annual test during the period April to December 1979 arose on brake pipes, reservoirs and so on; mechanical brake components; obligatory stop lamps; smoke emission; oil leaks; transmissions; suspension (attachments); fuel tanks and system; and steering linkages.