§ Mr. G. M. Thomsonasked the Minister of Transport if he will state, in connection with the regulations making it an offence for a driver to produce excessive diesel smoke, how many lorries have been taken out of service at the check points during the most recent convenient period, and how many others have been warned about bringing their engines within the regulation.
§ Mr. Marples83,000 diesel lorries were observed in three special nationwide surveys this summer, of which 9,800 were emitting black smoke. 132 were taken out of service immediately and 3,900 were threatened with prohibition unless they later satisfied a second test. In addition, 4,000 warning letters were sent.