§ Mr. Bradleyasked the Secretary or State for Transport whether he will make available the results of trials of heavy goods vehicles which he has been carrying out.
§ Mr. William Rodgers:My Department, using the services of the Transport and Road Research Laboratory, has reported to me the results of some limited trials of articulated goods vehicles. The aim of these trials has been to make a comparison, from a safety and environmental standpoint, between the performance of lorries of a higher gross weight than currently permitted in this country with that of lorries which are permitted.
Seventeen vehicle combinations were tested in the trials. This was too small a sample for firm conclusions. However, the trials do point to certain tentative conclusions which merit further consideration and study.
The test results suggest that in respect of braking stability, general drive and handling characteristics, noise and smoke emissions and use of energy, there is little to choose between the heavier and lighter combinations. However, the heavier vehicles appeared not to be as good in braking performance and had less resistance to roll-over. There were also problems, in certain cases, in distributing the load so as not to exceed a weight of 10 tonnes on the drive axle.
As soon as the report of the trials can be printed, I shall arrange for it to be published and for copies to be placed in the Library of the House. In the meantime, I am considering what further study and work might usefully be put in hand to throw more light on the relevant issues.