Analysis of roadway departure crashes on two-lane rural roads in Texas.

PDFTech ReportFHWA/TX-11/0-60311Project 0-6031-1Ran off road accidentsTraffic accidentsTwo lane highwaysRural highwaysTraffic safetyHighway safetyTexasTexas. Dept. of Transportation. Research and Technology Implementation OfficeLord, DominiqueBrewer, Marcus A.Fitzpatrick, KayGeedipally, Srinivas R.Peng, YichuanTexas Transportation InstituteTexas. Dept. of Transportation. Research and Technology Implementation OfficeUnited States. Federal Highway AdministrationUS Transportation Collection"This three-year research effort was undertaken to identify factors that influence the number and severity ofroadway departure crashes on rural two-lane highways in Texas and provide engineering countermeasures toreduce this type of crash. The study objectives were accomplished by analyzing crash, traffic flow, andgeometric data between 2003 and 2008 and conducting site visits at 20 sites having the highest crash rates atfour TxDOT districts.The study results showed that the proportion of roadway departures varied from 25 percent to 52 percent forall crashes occurring on the rural two-lane highway network. Proportionally more crashes occur onhorizontal curves than on tangents and during nighttime. Distracted driving and speeding were found to beimportant contributing factors.To help reduce the number and severity of roadway departures, the research team proposed several medium tolow-cost countermeasures that can realistically be implemented by TxDOT. These countermeasures weregrouped into three categories: targeted for horizontal curves, general applications, and new and innovativetreatments. For each treatment, the information focused on the general characteristics, key design features,safety effectiveness, cost (when available), and additional resources where the reader can find more detailedinformation about the treatment. More than 25 treatments were described for reducing roadway departurecrashes.