Cost-effective safety treatments for low-volume roads.

Final report.PDFTech ReportTRP-03-222-12SPR-3 (017) Supplement #35Low volume roadsTraffic accidentsCulvertsSlopesDitchesDrivewaysBridgesTreesBenefit cost analysisRoadside hazardsSafety engineeringRoadside improvementNebraskaMidwest States Regional Pooled Fund ProgramNebraska. Dept. of RoadsSchrum, K.D.Lechtenberg, K.A.Stolle, C.S.Faller, R.K.Sicking, D.L.Midwest Roadside Safety FacilityUnited States. Federal Highway AdministrationNTL-HIGHWAY/ROAD TRANSPORTATION-HIGHWAY/ROAD TRANSPORTATIONNTL-SAFETY AND SECURITY-Highway SafetyUS Transportation CollectionThe majority of roadside safety guidance pertains to high-volume roads. Very little guidance exists to assist engineers intreating common obstacles found alongside low-volume roads. In general, it is assumed that low traffic volumes can effectivelymitigate the risks associated with vehicle impacts into fixed objects and other geometric features to a point where they do notsignificantly increase the accident costs relative to high-volume roads. However, a single crash on a low-volume road may resultin a fatality or a severe injury, effectively making low-volume roads competitive in severity scale with high-volume roads. As aresult, the possibility of a fatal or severe injury crash needs to be mitigated on low-volume roads.Common roadside features were observed in a field study and included culverts, trees, slopes, ditches, and bridges. Aprobability-based encroachment tool, known as the Roadside Safety Analysis Program (RSAP), was used to determine impactfrequencies and severities for each feature. Treatment options, like removing the fixed object or installing W-beam guardrail, wereconsidered for each feature. Finally, acceptable ranges in traffic volume were recommended for each safety treatment option. Inthese recommendations, the \ue2\u20ac\u153do nothing\ue2\u20ac? option was often considered to be the most cost-effective safety treatment for theexisting configuration. However, this was not always the case