Heavy vehicle safety performance

Abstract

Significant benefits have been realised in South Africa from adopting the PBS framework in the form of reduced fuel consumption, CO2 emissions, road wear, trips and crashes. Three representative baseline PBS vehicles were developed (a quad-axle semitrailer, tri-axle interlink and rigid drawbar combination) and a set of ranges within which each vehicle design parameter (VDP) could be varied was developed. Each VDP for each baseline combination was varied in isolation to determine its effect on the vehicles PBS performance. The degree to which each VDP affected each performance measure in relation to each other is presented in a matrix for each of the baseline vehicles. The matrices indicate that the geometrical and inertial properties of the vehicle dominate vehicle performance and should be optimised before looking at suspension and tyre properties. The matrices yield insight into which VDPs have the most influence on each performance measure as well as which VDPs can be conservatively estimated in the absence of OEM data without significantly degrading the simulated vehicle performance.