In the late 1980s the poorly understood speed derestriction sign was replaced by the 100 km/h sign in some States of Australia to indicate entry onto a section of road on which the General Rural Speed Limit applied. This paper describes four surveys conducted among drivers and practitioners that provide evidence that drivers have difficulty understanding this sign when used on roads where speeds of 100 km/h are not possible. The surveys comprise an overseas survey, a practitioner survey, a motoring organisation member survey and a driver survey. It is concluded that a new sign is needed to replace both the derestriction sign and the 100 kmn/h sign in areas where speeds of 100 km/h are not possible or desirable. are not possible or desirable. Based on international practice and an examination of the possible alternatives, it is suggested that the sign should be of the form of a speed limit sign (the speed limit of the zone being left), crossed by five diagonal lines. (A)
Samenvatting