Study Details
Study Title: Empirical Bayes before-after evaluation of horizontal curve warning pavement markings on two-lane rural highways in Pennsylvania
Authors: Wood and Donnell
Publication Date:AUG, 2020
Abstract: Roadway departure crashes contribute to a large proportion of fatal and injury crashes in the United States. These crash types are more likely to occur along horizontal curve sections of a roadway. Countermeasures that prevent vehicles from departing the roadway is one method to mitigate roadway departure crashes. Pennsylvania has deployed on-pavement horizontal curve warning markings in advance of horizontal curves on two-lane rural highways as a roadway departure crash reduction strategy. This study used an Empirical Bayes (EB) before-after study design to evaluate the safety effects of the horizontal curve warning pavement markings. A total of 263 treatment sites and more than 21,000 reference sites were included in the evaluation. Crash modification factors were developed for total, fatal plus injury, run-off-road, nighttime, nighttime run-off-road, and nighttime fatal plus injury crashes. The point estimates for each of these crashes ranged from 0.65 to 0.77 – the results were statistically significant for total and fatal plus injury crashes at the 95th-percentile confidence level.
Study Citation: Wood, J. and E.T. Donnell. "Empirical Bayes before-after evaluation of horizontal curve warning pavement markings on two-lane rural highways in Pennsylvania". Accident Analysis and Prevention, Vol. 146, (2020) 105734.
Study Report: Download the Study Report Document
CMFs Associated With This Study
Category: Delineation
Countermeasure: Install in-lane curve warning pavement markings
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|---|---|---|---|---|---|
| 0.652 | 34.8 |  | All | All | Principal Arterial Other | Rural |
| 0.693 | 30.7 | | All | K,A,B,C | Principal Arterial Other | Rural |
| 0.769 | 23.1 | | Run off road | All | Principal Arterial Other | Rural |
| 0.708 | 29.2 | | All | All | Principal Arterial Other | Rural |
| 0.745 | 25.5 |  | Run off road | All | Principal Arterial Other | Rural |
| 0.771 | 22.9 | | All | K,A,B,C | Principal Arterial Other | Rural |
