Response to Interstate 10 crossover crashes

The Arizona Department of Transportation takes seriously all collisions on state highways, including cross-median crashes, which are a small percentage of serious crashes on the Interstate 10 corridor between Phoenix and Tucson. ADOT’s Traffic Safety Section, along with the Federal Highway Administration, is currently implementing a Roadway Departure Safety Plan that will help reduce cross-median and other roadway departure crashes on highways across the state.

ADOT is also working on the I-10 corridor between Phoenix and Tucson by implementing improvements indicated in a detailed Interstate 10 Corridor Study completed by ADOT in 2010. Improvements already constructed or under design will increase capacity and enhance safety by widening the roadway through the addition of lanes, and constructing barriers where indicated by ADOT and national standards along multiple stretches of I-10 between Phoenix and Tucson.

ADOT’s median-barrier standards are consistent with or exceed the standards used by most states to determine when a median barrier should be constructed. These standards are based on research that shows on wide medians, a barrier becomes a relative safety hazard rather than a safety feature. This is because they reduce the open median space available where most drivers departing the roadway can recover control without colliding with an obstruction. While cross-median crashes are frequently severe, collisions with median barriers are more frequent and can also be fatal. For this reason, even after the completion of improvements, many sections of the I-10 corridor will continue to have an open median.

Neither the federal government nor the majority of states have a method of continuously tracking cross-median crashes. In the past, ADOT has conducted traffic studies to determine the number of cross-median crashes. ADOT has recently updated its crash reporting form that police officers are required to fill out when investigating any serious collision to include a cross-median descriptor. This will allow us to more easily determine the number of cross-median crashes at or near a given location through ADOT’s computerized crash tracking system.