§ Mr. Sillarsasked the Secretary of State for the Environment what conclusions were drawn by report 582 of the Transport and Road Research Laboratory; and what further work is being undertaken on gross vehicle weight and suspension design.
§ Mr. CarmichaelReport LR582 of the Transport and Road Research Laboratory is concerned with dynamic loads and vibrations produced by heavy commercial vehicles. This work shows that the dynamic properties of the vehicle suspension system influence the dynamic loads and vibrations produced in roads and bridges. The magnitudes of the dynamic loads are dependent on the vehicle speed and the size of the irregularities in the path of the vehicle, even a smooth road surface showing variations in measured axle load of 15 per cent. above static values. Further work aimed at achieving a better understanding of vehicle suspension dynamics is continuing.