Driver Understanding of Potential All-White Pavement Marking Patterns

Over the last decade, increasing attention has been devoted to the potential of converting U.S. pavement markings to an all-white system. There are many reasons and potential benefits for doing so. As part of an NCHRP study, researchers conducted many activities to evaluate the feasibility of implementing an all-white marking system in the United States. The research study findings on marking practices in other countries and the results of the driver survey on all-white markings are summarized here. The researchers found that 17 of the 22 countries contacted use an all-white marking system. However, numerous differences exist between the systems used in various countries, so there is no single all-white system on which the United States could base implementation. The survey findings indicate that the all-white markings evaluated in the survey did not have any higher comprehension levels than the current system of yellow-white markings. Therefore, implementation of all-white markings would need to be accompanied by an extensive driver education program. The survey findings indicate that the presence of a solid line as part of the centerline increases understanding of the two-way message of a centerline to about 85%. In developing the survey, the researchers determined that the use of various marking widths or stripe-gap ratios was not effective in conveying messages to drivers. On the basis of the study findings, the researchers recommended an all-white system not be implemented in the United States at this time.