MINIMUM RETROREFLECTIVITY FOR PAVEMENT MARKINGS BY DRIVER'S STATIC TEST RESPONSE

Visibility plays a important role in nighttime accidents and fatalities. Pavement marking retroreflectivity provides adequate visibility at long distances to allow a driver enough time to acquire and process the navigational information. It is important to replace the pavement marking prior to the time when they no longer meet the needs of the nighttime driver. To maintain nighttime visibility, pavement markings should be maintained by the responsible highway agencies. The ways to determine the appropriate level of retroreflectivity needed by nighttime drivers and replacement timing are not proposed. The objective of the experiment described here was to obtain the visibility of pavement markings by subjects. Both quantitative measurements of pavement marking samples especially manufactured and subjective evaluations by 49 subjects during the static test were conducted. The effects of color and material retroreflectivity range were considered. After completion of the experiment, the minimum in-service level from a driver?s point of view, 130 mcd//lx for white markings and 110 mcd//lx for yellow markings, was established.