Accident research has shown that the horizontal curve is often a factor in vehicle crashes, especially on rural roads. A high proportion of the accidents happen at night and usually involve a single vehicle that runs off the road. Sharp curves on high speed rural roads tend to be more hazardous for drivers and therefore require enhanced driver information. Alignment information on such curves is improved by the use of Chevron Alignment Markers (single black chevron on yellow background) popularly known as CAMs. Scientific studies regarding the application and performance of CAMs in actual field use are relatively few. The application of CAMs, therefore, has largely been based on experience and judgement. Consequently, therehas been a range in quality of the use of this device in the field. This paper reports field studies by the Roads and Traffic Authority of New South Wales to examine the existing practice in the use of CAMs and recommendations for their proper use. The studies were seen as a contribution to revision of Australian Standard AS1742.2, Manual of Uniform Traffic ControlDevices, Part 2 - Traffic Control Devices for General Use, by Standards Australia Committee MS/12. (A)
Abstract