ATSSA: Improving Driver Behavior with Infrastructure Safety Countermeasures

11 American Traffic Safety Services Association • www.atssa.com Figure 16. Glass beads being applied during a double-yellow-centerline plural- component epoxy application (Image: ATSSA Pavement Marking Division) Additional details on pavement markings can be found in the Manual on Uniform Traffic Control and in the Roadway Delineation Practices Handbook. Wider pavement markings are effective in improving safety. Data from New York state revealed a 10 percent decrease in total crashes and a 33 percent decrease in fixed-object crashes. This was observed when 8-inch-wide pavement markings were used as opposed to standard 4-inch- wide markings. Similarly, the Texas Transportation Institute (TTI) found that in Michigan, wider markings produced reductions for all crash types, including a 24.6 percent reduction in fatal and injury crashes, a 39.5 percent reduction for crashes at night and a 33.2 percent reduction in wet crashes at night. The dimensions of wider markings can vary, ranging from 5 inches to 8 inches, with 6 inches being the most commonly used according to a TTI study. The cost of a wider pavement marking is generally 20 percent to 50 percent higher than standard markings, which can cost between 10 cents and $2.35 per foot, depending on the location and materials, which may include paint, thermoplastic plural-component epoxies and polyureas, and preformed tape. Raised pavement markers are reflective markers that are used on longitudinal lines to provide additional visibility and delineation and can also provide an auditory warning when driven over. These markers can be installed in a raised position on the pavement or in a recessed groove within the pavement to allow for snowplowing in winter months. Positioning longitudinal pavement markings in recessed grooves also protects the reflective glass beads or other reflective media from snowplow damage and excessive tire wear, thereby enhancing the service life of the marking. Even where standard, nonreflective pavement markings may be used, they have been shown to have a positive effect on safety. Using data from a number of different states, it was found that an average crash reduction of 21 percent can be attributed to pavement markings. The addition of an edge line, where one is not already present, has also been shown to be a low-cost solution that improves safety and should be considered by local jurisdictions — especially those with numerous rural roads. Figure 17. Fresh pavement markings safely guide motorists on a rural Virginia road (Image: James Scott Baron, ATSSA) All pavement markings can be beneficial, but by their nature, they will wear out, fade, and lose their effectiveness over time. It is critical that agencies have a plan in place to maintain pavement markings and upgrade them when necessary to maintain the greatest roadway safety impact. The plan should consider traffic conditions, environmental conditions, and potential safety needs. Whenever pavement markings are installed or rehabilitated, they should incorporate retroreflectivity performance to the greatest extent possible for the safety of all motorists. For some types of markings, such as liquid pavement markings (paint, plural-component epoxies, polyureas, and thermoplastic), this is achieved by adding highly reflective glass beads onto the liquid binder. For other types of markings, such as preformed tape, the pavement marking material already contains retroreflective beads that are built into the product. ■