Overtaking behaviour on narrow two-lane two way rural roads.

The experiment technique was to observe and record the behaviour using a video recorder and to digitally log information onto the screen. It was concluded that the mean overtaking time was increased and that the 85th percentile overtaking time was increased by 18 per cent on the narrow roads. This caused an increase in the calculated establishment sight distance of 12 per cent. Mean safety margins were unaffected. The difference in the behaviour of motorists during various sections of the manoeuvre were also discussed.