Author(s):
P.J. Carlson, J.D. Miles, A.M. Pike, E. Park
Publication Date
August 2007
Abstract
This report details the completion of a 30-month project investigating wet-night and contrast pavement markings. The first year report contains the literature review on wet-night markings and the Phase I effort on wet-night pavement markings. This report contains the Phase II effort on wet-night pavement markings, a benefit-cost analysis, and a study of contrast markings. Phase II effort consisted of expanding the study design from Phase I to include additional wet-night pavement marking products, the effects of glare and dry pavement on detection distances, and a benefit-cost analysis with respect to the use of different pavement markings systems to accommodate drivers under wet-night conditions. In the contrast study, a literature review of contrast markings, a state-of-the-practice with respect to contrast markings, and a study of driver understanding and preference with respect to contrast markings were all conducted. After studying multiple wet-night pavement marking products used in the state of Texas, it was found that reflectorized raised pavement markings provided the most preview time under wet-night conditions. The rumble stripe and the use of bigger beads such as Type III do provide improved wet-night detection distance, and in reference to cost, the use of bigger beads on a flat line, or a rumble stripe in conjunction with RRPMs provides an effective wet-night performance. Contrast markings were found to be used in 64 percent of the districts in Texas and in 64 percent of the responding states. The most frequently used contrast marking design is the bordered design where a white marking is highlighted with black markings along the longitudinal sides. While driver preference suggests that the shadow design is less preferred to the bordered design, the shadow design is normally a more cost-effective design, considering maintenance of the marking. The findings show that the bordered design is preferred. While this design is currently provided with tape products, which have a high initial cost, a non-tape marking alternative is the shadow design, which has fewer maintenance concerns than other non-tape applications. The use of only these two designs is also recommended to limit the number of contrast marking designs in hopes of minimizing driver confusion (this study showed that some drivers do not understand the meaning of the contrast markings).
Report Number:
0-5008-2
Keywords:
Benefit-cost, Contrast, Durability, Night, Pavement Marking, Rainfall Rates, retroreflectivity, RRPM, Rumble Stripe, visibility, Wet
Link(s):
Document/Product
http://tti.tamu.edu/documents/0-5008-2.pdf
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