| Title | Reducing Roadway Departure Crashes at Horizontal Curve Sections on Two-lane Rural Highways |
|---|---|
| Record ID | 74722 |
| Personal Name Creator |
Donnell, Eric T.; Porter, Richard J.; Li, Lingyu; Hamilton, Ian; Himes, Scott; Wood, Jonathan |
| Personal Name Contributor |
Cheung, Joseph |
| Corporate Creator | United States. Department of Transportation. Federal Highway Administration. Office of Safety |
| Corporate Contributor |
Thomas D. Larson Pennsylvania Transportation Institute; VHB/Vanasse Hangen Brustlin, Inc. |
| Publisher | United States. Department of Transportation. Federal Highway Administration. Office of Safety |
| Publication Date | 20190101 |
| Language | English |
| Abstract | While several proven safety countermeasures and strategies exist to mitigate roadway departure crashes on horizontal curve sections of two-lane rural highways, there are several countermeasures or strategies that have yet to be proven via a rigorous safety evaluation. The purpose of this research was to identify several of these strategies or countermeasures, and to perform a statistical assessment of their safety effectiveness. This report details the following three evaluations: (1) observational before-after study of curve ahead warning pavement markings, (2) cross-sectional study of delineators on guiderail along horizontal curves, and (3) cross-sectional study of the safety effects of geometric design consistency. The findings from these evaluations indicate that the expected number of roadway departure crashes are associated with the horizontal curve radius, radii of adjacent horizontal curves, and the tangent lengths between curves. Further, the expected number of roadway departure crashes is associated with side friction demand on horizontal curves. Guiderail with delineators are expected to reduce total, fatal plus injury, run-off-road (ROR), and nighttime crashes along horizontal curves that are four degrees or sharper. Horizontal curve warning pavement markings are associated with fewer expected total, fatal plus injury, ROR, nighttime, nighttime ROR, and nighttime fatal plus injury crashes on two-lane rural highways. |
| Rosap ID | dot:55604 |
| Rosap URL | https://rosap.ntl.bts.gov/view/dot/55604 |
| TRT Terms | Ran off road crashes; Traffic safety; Highway curves; Rural highways; Two lane highways |
| General Subjects | Traffic safety; Horizontal curves; Roadway departure; Design consistency; Delineators; Guiderail; Curve warning pavement markings; Empirical Bayes; Propensity scores |
| Geographical Coverage |
United States |
| TRIS Online Accession No |
1773464 |
| Contract Number | DTFH61-12-C-00032 |
| Report Number | FHWA-SA-19-005 |
| Resource type | Tech Report |
| URL | https://ntlrepository.blob.core.windows.net/lib/74000/74700/74722/FHWA-SA-19-005.pdf |
| Format | |
| Database | NTL Digital Repository |