Study Details
Study Title: Safety Evaluation of The Safetyedge Treatment for Pavement Edge Drop-Offs on Two-Lane Rural Roads
Authors: Lyon et al.
Publication Date:JAN, 2018
Abstract: This study estimated crash modification factors (CMFs) for the SafetyEdge paving technique that is applied for the treatment of pavement edge drop-offs on two-lane rural highways. An empirical Bayes observational before-after evaluation based on installation data in Iowa, North Carolina, Ohio, Pennsylvania and Florida found that the SafetyEdge treatment was associated with statistically significant reductions in fatal and injury (FI), run-off-road (ROR), opposite direction (head-on and sideswipe), and drop-off-related crashes. The ROR CMF was also statistically significant for both horizontal curve and tangent sections. A disaggregate analysis examined the variation of the CMF for ROR with factors such as the travel lane width, traffic volume, presence of a horizontal curve, posted speed limit, and the pre-treatment ROR crash frequency. The results of that analysis indicated, for example, that the SafetyEdge paving technique appears to have a greater ROR safety benefit on two-lane rural roadway segments with average annual daily traffic volumes greater than 3,000 vehicles per day, relative to roadway segments with lower traffic volumes. A Crash Modification Function was calibrated with expected pre-treatment ROR crashes as the independent variable to simultaneously capture the relationship of the CMF for ROR crashes to multiple factors. An economic analysis found that the treatment is highly cost effective.
Study Citation: Lyon, C., B. Persaud, and E. Donnell. "Safety Evaluation of The Safetyedge Treatment for Pavement Edge Drop-Offs on Two-Lane Rural Roads". Presented at the 97th Annual Meeting of the Transportation Research Board, Paper No. 18-00673, Washington, D.C., (2018).
Related Citations: Donnell, C., C. Lyon, B. Persaud, F. Gross, and K. Eccles. "Development of Crash Modification Factors for the Application of the SafetyEdge on Two-Lane Rural Roads". Federal Highway Administration, Washington, D.C., (pending publication).
CMFs Associated With This Study
Category: Shoulder treatments
Countermeasure: Install safety edge treatment
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|
| 0.989 | 1.1 |  | All | All | Not specified | Rural |
| 0.79 | 21 |  | Run off road | All | Not specified | Rural |
| 0.813 | 18.7 | | Head on,Sideswipe | All | Not specified | Rural |
| 0.981 | 1.9 | | Run off road | All | Not specified | Rural |
| 0.917 | 8.3 | | Run off road | All | Not specified | Rural |
