110 KILOMETRE PER HOUR SPEED LIMIT - EVALUATION OF ROAD SAFETY EFFECTS

On 1 June 1987 Victoria raised the speed limit on its 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 limit was reintroduced. Results were an increase in injury accident rate (including fatalities) per km travelled of 24.6% when the speed limit was introduced in 1987 and a decrease of 19.3% when it was removed in 1989. These results were with comparison to a control group. Similar results were found in sub-groupings by urban/rural groups, standard of freeway and accident severity. 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 a dampening effect on speeds with beneficial road safety results.