Rationalisation of speed limits within the Safe System approach

This paper summarises the calculation of the optimum speeds for the range of Australian rural road types: rural freeways, multi-lane divided roads, and single-lane undivided roads, with and without shoulder-sealing. The system-wide impacts if cars and trucks were to travel at their optimum speeds, as a basis for setting speed limits in each road environment, are then calculated. A rationalisation of speed limits to reflect the innate expectations of drivers, but also based on rational analysis of all the costs and benefits, may result in greater compliance with speed limits and make intensive speed enforcement more palatable and even unnecessary long-term.