Abstract
Centerline raised pavement markers (RPM) have emerged as a justifiable rural road safety countermeasure for preventing run-off-road (ROR) and opposite-direction crashes. These devices supplement lane markings, enhance positional guidance, alert drivers to changes in roadway geometry, and reduce encroachment. This research evaluated the safety effect of centerline raised pavement markers (RPM) installed on rural roads in Indiana and proposed a practical and systemic approach for identifying road segments that require more attention. To support the Indiana Department of Transportation (INDOT) in this task, the study develops a set of Crash Modification Factors (CMFs) that reflect the safety effects of installing raised pavement markers on the target crashes.
The analysis is based on crash data collected from Indiana rural two-lane roads during the 2015-2023 period, which comprised more than 20,000 crashes across over 8,000 roadway segments. In addition to the effect of RPMs, the study also investigated the joint safety effects of RPMs and other countermeasures, including rumble strips (RS) and shoulders and lane widths. The results help determine the joint effect of any combination of these road cross-section features on reducing the crash occurrence and severity.
A panel analysis (cross-sectional combined with before-and-after analyses) through a negative binomial model with random effects was implemented to safety-related data from two-lane rural roads during the studied nine-year period. The safety effects across sites with and without raised pavement markers were estimated while controlling local factors such as traffic volume and road geometry.
This study confirmed a statistically significant reduction in ROR crashes associated with the implementation of raised pavement markers (RPMs) equal to 15% at daytime and 11% at nighttime on average across the treated Indiana roads. The opposite-direction collisions, including head-on and opposite-direction sideswipe crashes, were significantly reduced at nighttime by nearly 22%. The daytime opposite-direction crashes showed no significant change after RPMs implementation.
Keywords
raised pavement markers, run-off-road crash, opposite direction crash, CMF, rumble strips, crash frequency, crash severity
Report Number
FHWA/IN/JTRP-2025/41
SPR Number
4852
Sponsoring Organization
Indiana Department of Transportation
Performing Organization
Joint Transportation Research Program
Publisher Place
West Lafayette, Indiana
Date of Version
2025
DOI
10.5703/1288284318606
Recommended Citation
Florez Forero, L., Bandaru, V. K., Romero, M., & Tarko, A. (2025). Safety performance of centerline raised pavement markers (Joint Transportation Research Program Publication No. FHWA/IN/JTRP-2025/41). West Lafayette, IN: Purdue University. https://doi.org/10.5703/1288284318606
SPR-4852 Technical Summary