Assessing 'road-friendliness' : a review

This paper is concerned with assessing the dynamic tyre forces generated by articulated heavy goods vehicles for road damaging potential. Various factors are discussed, including: (a) general testing methodologies; (b) road damage issues such as 'spatial repeatability' of dynamic tyre forces and road damage criteria; (c) vehicle response issues, such as test duration and sampling details, road roughness, testing speed, wheel-base filtering, tractor-trailer interaction, suspension maintenance and 'indirect' testing methods; and (d) implementation issues. It is concluded that the most practical method ofassessment testing would be to use a 'type approval' test to measure the vehicle's peformance when coupled to a standard trailer or tractor unit, combined with anual inspections of hydraulic damper integrity. The type approval procedure should use simple single-axle laboratory tests to estimate the parameters ofa generic mathematical model of each vehicle unit. Numerical simulations of the tractor and standard trailer (or trailer and standard tractor) should be used to determine the vehicle's response to a variety of typical road input conditions. These responses should than be assessed using realistic road damage criteria to determine an 'in-service' road damage index.