Vast travel distances and extremely low traffic volumes have regularly led to calls in some parts of Australia for the introduction of higher speed limits on rural and remote roads (currently 100 or 110 km/h). This report, based on a review of existing documentation and data, looks at the likely effects of increasing the current maximum rural speed limit. Most previous work relating to the topic of changing speed limits is not directly relevant to the Australian situation. The main reasons are that most studies relate to reductions in speed limits rather than increases and speed limits on undivided rural roads in Australia are higher than in almost every other country. Also, many previous studies have not differentiated between the terms `speed' and `speed limit'. From a `first principles' analysis, the report suggests that actual travel time savings resulting from increased speeds brought about by an increased speed limit are likely to be small, and serious doubts are raised about the proposition that higher travel speeds result in greater driver alertness. The report concludes that it is likely that an increase in the speed limit on rural and remote highways in Australia would result in an increase in vehicle speeds, with a consequent increase in accident numbers and severity. It is not possible to give quantitative estimates of the likely increases in speed and accidents. (A)
Samenvatting