Further evaluation of the South Australian default 50 km/h speed limit

Abstract

On 1 March 2003 the default urban speed limit in South Australia was reduced from 60 km/h to 50 km/h. On-road speeds just before the default limit was introduced were compared with speeds one and three years later. The number of casualty crashes and casualties in the three years before the default limit was introduced were compared with corresponding numbers in the three years after the default limit came into effect. On roads where the speed limit was reduced from 60 km/h to 50km/h, average speeds decreased by 3.8km/h after three years and casualty crashes fell by 23 per cent. On roads where the speed limit remained at 60 km/h, average vehicle speeds decreased by 2.1 km/h after three years and casualty crashes fell by 16 per cent.