This is a follow-up study to one undertaken in 1983 which set out to show the influence of rut depth on vehicle control under winter road conditions, using computer simulation techniques. In this present work two different types of vehicle manoeuvre were examined in order to determine "critical" friction levels. In the first manoeuvre, the vehicle crossed over at an angle to the left of the road with no turning movement. The second manoeuvre corresponded to the initial phase of various types of sudden overtaking. Each manoeuvre was examined at 2,4 and 6cm rut depth and the friction coefficient at which the vehicle started to skid was determined. Results indicated that an increase of 2 cm in rut depth corresponded to a reduction of 1% in the coefficient of friction. However in the model used no attention was paid to driver behaviour and it is therefore recommended that further studies be made using a driving simulator.
Abstract