Evaluation of Driver Comprehension and Compliance of Red-Colored Pavement Markings for Transit Lanes in Portland, Oregon

Many U.S. agencies have experimented with red-colored pavement markings in transit lanes to enhance the message that they are restricted to transit vehicles. This study evaluated nontransit drivers' comprehension of and compliance with red-colored lane markings in transit priority lanes intended to communicate lane restrictions and appropriate turning and merging locations. Two complementary research methods were used: 1) an online survey of drivers' comprehension of red-colored pavement markings, and 2) evaluation of video collected at locations pre and post installation of red-colored pavement markings. In the survey, most drivers recognized the red pavement color as a restriction on use, but most did not associate it specifically with transit, or understand the intended meaning of the broken red bar patterns designed to designate a merge area. However, we observed relatively high compliance rates with the transit lane restrictions, and the red pavement coloring was generally associated with improved compliance. Of the 22,803 vehicles observed at these locations, 206 were observed driving in the transit lanes, accounting for a violation rate of 0.9%. For the locations with pre and post data, driving-in-transit-lane violations were either reduced or there was no significant change. For locations with shared turn and transit lanes, between 62% and 76% of drivers merged as intended, and we observed an increase in appropriate merging behavior with the addition of red pavement color.