NCJ Number
140631
Date Published
1992
Length
39 pages
Annotation
On June 1, 1987 Victoria (Australia) raised the speed limit on its rural and outer Melbourne freeway network to 110 kilometer per hour (km/hr) from 100 km/hr. In late September 1989 the limit was removed and a 100 km/hr limit was reintroduced. This study examines the impact of these changes.
Abstract
Approximately 2 1/2 years of "before 110," "during 110," and "after 110" casualty accident data were used (a casualty accident is one where at least one person was injured or killed). A before and after study design with control groups was used with the main reporting variable being casualty accident rate per kilometer traveled. Available speed data and literature were also reviewed. Study results indicated an increase in injury accident rate (including fatalities) per kilometer traveled of 24.6 percent in the "before 101" to "during 110" period and a decrease of 19.3 percent in the "during 101" to "after 110" case. These findings were compared to a control group. Results by urban/rural groups are also presented. The study estimated that under a mature 110 km/hr regime, approximately 50-60 percent of cars exceeded 110 km/hr, and 12-20 percent exceeded 120 km/hr. A 100 km/hr speed limit is assessed as having dampening effect on speeds with beneficial road safety benefits. 2 figures, 6 attachments, and 12 tables