The 1978 heavy commercial vehicle speed and operational safety study - sponsored by ROSTA - resulted in a new speed limit structure for heavy commercial vehicles in victoria, in which speed limits for heavy trucks were set 10 km/h below the posted speed limits of 60 - 100 km/h for general traffic; subject to the condition that heavy trucks were limited to an overall maximum speed of 80 km/h. A study has been carried out to measure changes in car/ truck free speeds and accident patterns, before and after the change in speed limits in late 1978. This shows that whereas truck speeds have increased relative to car speeds, there is little overall change in car/ truck accident patterns. The exception is rural single- vehicle accidents involving articulated trucks, which have increased, and it is recommended that their speeds and accident frequencies (and exposures) be kept under review. (Author/publisher)
Abstract