As drivers, we are aware of the devices used by Traffic Engineers to present a better picture of the road and hence ease our driving task. Many products are used for this purpose and their characteristics and limitations are discussed in this paper.
At night, markings are dependent primarily upon vehicle headlights for visibility and must be efficient reflecting devices to be seen at useful distances.
Two principles of retroreflectance are described and their properties are compared. Relationship between the light source and the viewer's eye are covered.
Recent technology utilizing the triple-mirror type of reflector has greatly increased the assurance of driver guidance, particularly in the rain and other adverse weather conditions.
Examples of the installation of various types of delineations are shown. Accident data and cost/benefit ratios are discussed.