Toolbox of countermeasures for rural two-lane curves.

PDFTech ReportIHRB Project TR-579Two lane highwaysHighway curvesRural highwaysRan off road accidentsCountermeasuresHighway safetyPaved shouldersSingle vehicle accidentsSurface treatingTraffic control devicesIowaIowa State University. Institute for TransportationHallmark, ShaunaHawkins, NealSmadi, OmarIowa State University. Center for Transportation Research and EducationMidwest Transportation ConsortiumUS Transportation CollectionThe Federal Highway Administration (FHWA) estimates that 58 percent of roadway fatalities are lane departures, while 40percent of fatalities are single-vehicle run-off-road (SVROR) crashes. Addressing lane-departure crashes is therefore apriority for national, state, and local roadway agencies. Horizontal curves are of particular interest because they have beencorrelated with increased crash occurrence.This toolbox was developed to assist agencies address crashes at rural curves. The main objective of this toolbox is tosummarize the effectiveness of various known curve countermeasures.While education, enforcement, and policy countermeasures should also be considered, they were not included given thetoolbox focuses on roadway-based countermeasures. Furthermore, the toolbox is geared toward rural two-lane curves.The research team identified countermeasures based on their own research, through a survey of the literature, and throughdiscussions with other professionals. Coverage of curve countermeasures in this toolbox is not necessarily comprehensive.For each countermeasure covered, this toolbox includes the following information: description, application, effectiveness,advantages, and disadvantages