On 1 June 1987 Victoria raised the speed limit on it's rural and outer Melbourne freeway network to 110 km/h from 100 km/h. In late September 1989 the limit was removed and a 100 km/h was reintroduced. Results were an increase in injury accident rate (including fatalities) per kilometre travelled of 24.6% in the "Before 110" to "During 110" period and a decrease of 19.3% in the "During 110" to "After 110" case. These were with comparison to a control group. Results by urban/rural groups, standard of freeway and accident severity were also presented. Speed data and literature were reviewed and it is estimated that under a mature 110 km/h regime about 50-60% of cars would exceed 110 km/h and 12-20% exceed 120 km/h. A 100 km/h speed limit is assessed as having dampening effect on speeds with beneficial road safety benefits. (A)
Abstract