Identification of a discernable centerline rumble strip pattern based on audible and haptic location recognition to improve traffic operations and safety
Maintaining correct lateral position on roadways is critical for safe and efficient operation. The driving task comprises control, navigation, and guidance, all relying predominantly upon the sense of vision; however, not all traffic control devices rely on vision. Drowsy, distracted, or inattentive drivers may not have their "eyes on the road" and, are therefore, more reliant on other senses. One way that other senses have been used to assist drivers in maintaining a proper lateral position is through the use of rumble strips. Up until the late 1990's, rumble strips were primarily used on roadway shoulders; more recently, they are also being used in centerline applications as transportation officials attempt to address the high number of cross-over-centerline crashes that occur annually. In light of the effectiveness of shoulder rumble strips in reducing the number of roadway departure crashes, many states are using the same rumble strip pattern on both the shoulder and centerline, anticipating reductions in cross-over-centerline crashes. Findings of previously conducted research indicate that this duplication of signals may violate driver expectancy.
This research focuses on determining if a different pattern is beneficial to the driver, one that would allow a driver to determine their lateral position based on a rumble strip's audible and haptic cues. It was anticipated that if the pattern is discernable to drivers, then after repeated exposure, the strips would elicit a conditioned, correct response. A number of hypotheses were enumerated to assist in determining whether or not a unique rumble strip pattern would prove to be easily identified and would ultimately benefit the driver. To support or refute the hypotheses, research was performed in two evaluation environments, a static and a dynamic. Results from the evaluations indicate that a unique rumble strip pattern can aid drivers in maintaining their correct lateral position. Based on the opposite lane and shoulder incursions experienced in the dynamic evaluation environment, every driver responded properly. In instances where the incursion was accompanied with audible and haptic feedback, a result of the rumble strips, drivers were able to respond faster when compared to those incursions lacking multi-modality.