Evaluation of Traffic Marking Beads and Paint

About the report:

Traffic markings that retain high reflective properties under adverse lighting and weather conditions are clearly of utmost importance in traffic safety. It was the intent of this study to investigate optimum traffic striping procedures and materials by evaluating such variables as: (1) Certain characteristics of glass beads, namely their gradation and flotation properties; (2) Rate of bead application; and (3) Type of paint, including fast and slow drying paints. As a consequence of problems encountered with the control of the bead and paint application rates, the evaluation of the striping procedure and materials was limited. However, based on the results the following conclusions are presented: (1) Insufficient evidence was obtained to indicate that any one of the three bead types used was superior to the other in brightness under dry night conditions; however, it appears that the floating bead has an advantage over the non-floating bead under wet night conditions as the stripes with the floating bead were visible for further distances. (2) No clear advantage was noted for either of the two bead application rates used. (3) The fast drying paint used seemed to compare favorably with the slow drying paint, which supports the Department's decision for more extensive use of fast drying pavement marking paint in the immediate future. It is suggested that before additional in-depth studies are considered the results of a 1971 NCHRP Project entitled "Development of Optimum Specifications for Glass beads in Pavement Markings" be awaited, as many of the objectives of this NCHRP project should touch upon many of the unanswered questions in this report.

Authors