Relationship between speed and lateral position on curves.

PDFTech ReportPart of MTC Project 2009-03Traffic accidentsRural highwaysTwo lane highwaysHighway curvesSpeedingLateral placementAccident analysisData collectionUnited StatesMidwest Transportation ConsortiumHallmark, Shauna L.Iowa State University. Center for Transportation Research and EducationNTL-HIGHWAY/ROAD TRANSPORTATION-HIGHWAY/ROAD TRANSPORTATIONNTL-SAFETY AND SECURITY-AccidentsNTL-SAFETY AND SECURITY-Highway SafetyNTL-SAFETY AND SECURITY-Speed LimitsUS Transportation CollectionExcessive speed is often cited as a primary driver factor in crashes, particularly rural two-lane crashes. It has also been suggested that speed plays a significant role in crashes on curves.However, the relationship between speed and crashes on curves is not well documented because it is difficult to determine driver speed after the fact when investigating a crash. One method to begin documenting this relationship is to explore the relationship between lateral position and speed as a crash surrogate.For this study, the researchers collected speed and lateral position data for three rural two-lane curves. The relationship between lateral position and speed was assessed by comparing the odds of a near-lane crossing for vehicles traveling 5 or more mph over the advisory speed to those for vehicles traveling below that threshold