Reducing Head-On Crashes on FreewaysExecutive SummaryIntroductionHead-on crashes that occur on freeways are typically severe in nature and may be on the increase. A head-on crash typically occurs when a vehicle crosses the median and crashes with a vehicle traveling in the opposite direction (typically called a cross-median crash or median-crossover crash). A head-on crash can also occur when a vehicle inadvertently travels the wrong way in the opposing traffic lanes. Head-on cross-median crashes are typically the result of inadvertent actions by a driver potentially in combination with other adverse circumstances such as weather conditions or motorist fatigue. Recent experience and research has shown that a comprehensive approach to safety is most effective in creating a safer driving environment and improved effectiveness of safety treatments. A number of safety concerns including many related to head-on crashes cannot be as effectively solved by solely applying one of the "four E's" (engineering, education, enforcement, and emergency medical services) in isolation. When reviewing strategies dealing with head-on crashes, engineers should strongly consider the role of the other "four E" groups. To address the importance of considering a "four E" approach this document provides strategies that might be considered. General Description of the ProblemIn 2003, according to the FARS statistics, there were 366 fatal cross-median head-on crashes on U.S. freeways. In 2003 the total number of fatal crashes on Interstate routes was 4,813 with cross-median crashes representing almost 8 percent of the total. Although the number may seem small when compared to the number of overall crashes and to the percentage of all Interstate-related crashes, head-on crashes are extremely severe. This is illustrated by a recent study from the FHWA which considered the number of crossover fatalities on freeways on a national basis. From 1994 to 2002, while fluctuating annually, median-crossover and wrongway fatalities have increased by 17 percent (Ostensen, 2004). FHWA, in the memo, characterizes this increase as — "In many states, population growth in and around metropolitan areas has resulted in an increase in the vehicle-miles of travel and lane density, factors that may account for an increase in cross-median crashes on freeways approaching or circumventing urban areas. Nationally, the number of crossover fatalities on freeways, while fluctuating, has steadily increased from 581 in 1994 to 680 in 2002." In addition, it appears that a number of cross-median fatal crashes may have occurred at locations where some type of barrier was in place. Programs and StrategiesObjectivesThe objectives for reducing the number of fatal head-on crashes are to:
These objectives are similar to those cited for run-off-road crashes (emphasis area 15, Volume 6 of this guide) and head-on collisions (emphasis area 18.1, Volume 4 of this guide). Exhibit I-1 summarizes the objectives and strategies. For each objective identified (except for the last objective), there exist various strategies as listed in Exhibit I-1 below. Each strategy is described in detail in this guide. EXHIBIT I-1
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