HC Deb 25 January 1967 vol 739 cc278-9W
96. Mr. Driberg

asked the Minister of Transport when the working party set up to advise her on the revision of the Motor Vehicles (Construction and Use) Regulations will be considering the construction of articulated vehicles; and if she will draw to the attention of this working party the representations on this matter which she has received from the Barking Road Safety Council.

Mr. Swingler

Of the two points about the construction of articulated vehicles raised by Barking Road Safety Council, that on guards to prevent people being thrown under their wheels is on the agenda for the next meeting of the Working Party on the Construction and Use Regulations. The one about "jackknifing" has been under consideration by the Working Party on Brakes as "jackknifing" is closely related to the operation of the vehicles' braking systems.

Mr. Driberg

asked the Minister of Transport what percentage increase in the number of articulated vehicles licensed there has been in each of the past five years; to what extent the presence of these vehicles on the roads is a contributory cause of accidents; and what progress has been made in testing and fitting anti-jack-knifing devices.

Mr. Swingler

I regret that separate statistics showing the numbers of articulated vehicles licensed and the extent of their involvement in accidents are not available.

Progress towards preventing jack-knifing has included securing greater compatibility of the braking of tractor and trailer, by changes in the distribution of braking effort on the axle and by minimising wheel locking, particularly on the tractor rear axle.

Tests so far carried out with anti-jack-knifing devices, in particular load sensitive valves which adjust the braking effort on an axle to suit the load on that axle and other devices for preventing wheel locking, have shown these devices to be effective in the conditions of test. All such devices must, however, be more extensively tested over a long period under the wide variety of conditions arising in normal operation of the vehicles before their value can be fully assessed. Operators and manufacturers are cooperating in arranging such tests.