Quad trailer combinations comprising two semi-trailers and a B-double trailer set are becoming increasingly common throughout remote areas of Queensland and the Northern Territory. To further research into the on-road performance of multi-combination vehicles, and provide some insight into the optimum trailer configuration for the vehicles, Queensland Transport (QT) commissioned ARRB Group Ltd (ARRB) to conduct an investigation into the performance of an AAB-quad combination and a BAA-quad combination, composed of identical equipment. The investigation comprised an assessment of the performance of the vehicle by computer simulation, and also by on-road field testing. The investigation showed that both vehicles perform well, in general, and that there are very few differences between them in terms of performance. Both vehicles demonstrated similar performance in lateral acceleration gain and yaw damping test measures. In normal driving operations, it would be very difficult to identify any real difference. The only significant difference is in terms of the ability of the rear-trailer to resist rollover in an avoidance manoeuvre, as demonstrated by computer simulation. In this respect, the performance of the BAA-quad is considerably worse than that of the AAB-quad, because of reduced rearward amplification performance. (a) For the covering entry of this conference, please see ITRD abstract no. E217099.
Abstract