Abstract
Deceleration measurements of vehicles running into beds of loose gravel have been extended to include heavy vehicles, and to cover private cars at speeds up to 98.2 km/h (61 mile /h). At a given entry speed, mean values of deceleration obtained without application of a vehicle's brakes were found to be dependent upon the characteristics of the arrester bed including the size and shape of stone, but to be substantially independent of the vehicle type tested or its entry speed. The most promising use for arrester beds appears to be to provide escape routes from long-down-gradients for vehicles which experience brake failure.