Safety improvement from edge lines on rural two-lane highways : tech summary.

793654080Tech summary.PDFTech ReportLTRC Report 487Road markingsTraffic control devicesHighway traffic controlRural highwaysTraffic safetyTraffic accidentsLouisianaLouisiana Transportation Research CenterSun, XiaoduanLouisiana Transportation Research CenterNTL-OPERATIONS AND TRAFFIC CONTROLS-OPERATIONS AND TRAFFIC CONTROLSNTL-OPERATIONS AND TRAFFIC CONTROLS-Traffic Control DevicesNTL-SAFETY AND SECURITY-Highway SafetyUS Transportation CollectionThe previous study "Impact of Edge Lines on Safety of Rural Two-Lane Highways" completed in 2005 concluded that,with edge lines, centralization of a vehicle's position is more apparent during nighttime, which reduces the risk of runoff-road (ROR) accidents and head-on collisions, and edge line markings generally cause drivers to operate their vehiclesaway from the road edge, irrespective of the roadway alignment. Does the changed vehicle lateral position reducethe frequency of crashes? Answering this question is important to the Louisiana Department of Transportation andDevelopment (LADOTD) since implementing and maintaining edge lines on narrow two-lane highways require signifi cantresources from LADOTD. There are more than 40 percent of rural two-lane highways in Louisiana with a pavement width(excluding shoulders) of less than 22 ft. with no edge lines