This study evaluated the application of edge line rumble stripes (ELRSs) on rural, two-lane horizontal curves. This strategy was intended to reduce the frequency of run-off-road (ROR) crashes and nighttime crashes by alerting drivers that they are about to leave the traveled lane and by enhancing visibility of the edge line during nighttime and wet-weather conditions.
Several research studies have examined the use of shoulder rumble strips (SRSs); however, research into the performance of ELRSs is rare and has not been rigorously evaluated. Additionally, milled rumble strips are installed on roadway segments, consisting of both horizontal tangents and horizontal curves. Installations on only horizontal curves are uncommon and, therefore, safety effectiveness evaluations have not focused on their effectiveness on horizontal curves specifically. This research focused on the safety effectiveness of ELRSs on rural, two-lane horizontal curves, taken from rumble stripe installations that are not specific to horizontal curves. The full Techbrief is available at https://www.fhwa.dot.gov/publications/research/safety/17068/17068.pdf