A conunon cause of traffic accidents at low-volume rural intersections is failure by drivers on the minor approaches to stop or slow down sufficiently, as warranted. The current experimental field study compared the effectiveness of transverse paint stripes, such as those developed by the UK Transport and Road Research Laboratory, and similarly placed rumble strips in inducing drivers to reduce speed and stop at intersections. The experiment was conducted on the two minor approaches to the same four-way rural low-volume intersection. A geometrically converging pattern of 38 paint stripes, each 60 cm (2 ft) wide, were laid out over a distance of 270 m (886 ft) of one leg, and a similar pattern of rumble strips, 12 to 15 mm (1/2 to 5/8 in.) high, was laid on the opposite leg. A before-and-after and a crossover (after a year) experimental design were used. Speeds were monitored at eight points on each leg along 420 m leading to the intersection for a total of over 2,500 lead vehicles. The main results and conclusions are as follows:(a) paint stripes have only minor influence on driver behavior;(b) rumble strips lowered speeds by an average of 40 percent;(c) both treatments had a small positive effect on compliance rate;(d) with no pavement treatment, deceleration began at 150 m (492 ft) and peaked within the last 60 m (197 ft);(e) with rumble strips, most of the deceleration took place before the vehicle passed the first strip, followed by an additional deceleration within the last 60 m (197 ft); deceleration become uniform and moderate;(f) rumble-strip effects remained stable after a year; and (g) a 150-m (492-ft) treatment of 12-mm strips is long enough to produce the positive effects of rumble strips.

A conunon cause of traffic accidents at low-volume rural intersections is, apparently, driver failure to stop or yield on the minor approach legs of the intersections. It is generally believed that insufficient speed reduction during the approach phase plays a direct causal role in the generation of such accidents and in increasing their severity. Therefore, some of the measures for preventing accidents at such intersections, as well as at other critical locations such as sharp curves and highway work zones, are specifically designed to bring about vehicle speed reduction during the approach phase. Slowing down increases the likelihood of compliance with right-of-way rules (1); it improves the margin of safety in critical situations by allowing for more time and longer distances in case of an emergency stop, and it mitigates accident severity by reducing the energy levels in the case of a collision.