The objective of this study was to compare the performance of various types of materials, devices, and procedures that can potentially delineate roadways during wet, nighttime conditions. Snowplowable markers provide the most effective wet-nighttime delineation. Durability issues associated with the steel casting marker make the recessed marker preferable over the life of the pavement. Wet reflective tape placed in a groove provided both dry and wet-nighttime delineation and remained durable. The performance of thermoplastic material installed on the pavement surface supports its future use but will not provide wet-nighttime delineation. Inconsistent performance of inlaid tape argues against its expanded use. Poor performance shows that future use of wet-reflective tape should not be considered.

The research indicates an effective lane delineation procedure for four lane roads would include: recessed markers on lane lines (at 80-foot centers), grooved wet-reflective tape for lane lines, and spray thermoplastic for the edge lines. A cost analysis, considering durability of the materials, show that the cost of using more durable materials over the life of the pavement is not dramatically more than the cost of traffic paint. Edge line rumble stripes and centerline rumble strips enhance wet-nighttime delineation and should be incorporated into resurfacing projects on two-lane roads where pavement width permits.

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© 2016 University of Kentucky, Kentucky Transportation Center

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The contents of this report reflect the views of the author, who is responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the University of Kentucky, the Kentucky Transportation Center, the Kentucky Transportation Cabinet, the United States Department of Transportation, or the Federal Highway Administration. This report does not constitute a standard, specification, or regulation. The inclusion of manufacturer names or trade names is for identification purposes and should not be considered an endorsement.