Effect of Bigger Trucks on Mode Share
The argument that bigger and heavier trucks reduce the number of trucks on the road assumes that the freight market is static both in terms of the amount of freight and mode share. However, that is not the case. Increased truck payloads increase the competitiveness of road freight with respect to rail, stimulating a modal shift to road and countering any reduction in truck numbers brought about by higher payloads .
A report undertaken for Queensland Rail (QR) found that the widespread introduction of 36.5 metre, 90.5 tonne B-triple trucks on Queensland roads would result in the loss of most of QR’s contestable freight to road and a 160% increase in truck traffic all of which would be B-triples carrying freight previously transported by rail .
Diversion of traffic from rail to road leads to declining rail revenue and further decreases funds available for rail investment. Remaining rail customers face higher rates, reduced service or both.
Increases in truck size and weights are being considered only in the context of how they affect the efficiency of road freight operations. There is no consideration given to how these increases will improve the overall efficiency of the freight transport task and minimise the impact of transport on communities and the environment. Increases in truck size and weight has been occurring with no consideration at all of the likely impact on rail or of any federal, state or local government policies with regard to integrated transport planning or rail mode share targets. Truck size, particularly under the proposed introduction of Performance Based Standards (PBS), is assessed only against vehicle compliance with relevant technical and engineering standards.
Analysis of the Introduction of PBS
In early 2003, ARRB Transport Research undertook an analysis of the benefits of the introduction of PBS for heavy vehicles. The analysis found that the benefit/cost ratio to the road transport from the introduction of PBS was in the order of 5:1.
However, the analysis is incomplete because it failed to consider the impact on rail freight of bigger and heavier trucks and the consequent effect on mode share. The word ‘rail’ is referred to only once in the report and then ignored. The costs and benefits of PBS for the road transport sector need to include the adverse economic, social and environmental consequences of increased use of road freight.
The report is also deficient in not considering the adverse impact of accelerative force through the drive axle on road pavements. The impact of axle loads on road pavement was examined, but this is different from the damage caused by the drive axle of a heavy truck as it grips the road to accelerate or decelerate.