Horizontal curves - particularly those below 600 m in radius, those on two-lane rural roads, and those requiring a substantial reduction in speed from that prevailing on the preceding road section - are disproportionately represented among accident sites. Alerting the driver to the increase in hazard, through the use of warning signs, pavement markings or other visual aids to direction and curvature, is standard practice. However, choosing the optimum treatment or combination of treatments is difficult since relatively little is known of their effects on relevant driving behaviour. ARRB has devoted considerable research resources to this problem over the past three to four years. Other institutions, notably the Ohio State University in the USA, have similarly sustained major research effort on aspects of the problem. These research efforts are reviewed and the problem critically re-examined (A). The number of the covering abstract of the conference is IRRD 255423.
Abstract