Research Pays Off - Eliminating Cross-Median Fatalities: Statewide Installation of Median Cable Barrier in Missouri

Thirty years ago, a driver crossing the median of an Interstate roadway had a good chance of crossing over the opposing lanes without conflict. Today, according to Missouri data, a motorist crossing the median is more likely to collide with another vehicle, and the chances are high that the opposing vehicle will be a large truck.  To address this issue the Missouri Department of Transportation (DOT) research several options and decided to install a median cable barrier system on I-70 and on other Missouri Interstates. When the cable is struck, the posts yield and the cable deflects up to 12 feet, effectively catching and decelerating the vehicle and keeping it in the median.  The installation of median cable barrier costs $60,000 to $100,000 per mile, depending on the amount of grading work required. After the cable is installed, the maintenance costs range from $6,000 to $10,000 per mile per year, depending on the frequency of hits.  An internal Missouri DOT study determined that the cable catches 95 percent of vehicles entering the median and keeps the vehicles from entering the opposing lanes.  On Interstate 70, which links Kansas City and St. Louis, the number of cross-median fatalities had been increasing, reaching a peak of 24 motorists killed in 2002. The installation of 179 miles of median cable barrier on the freeway has nearly eliminated cross-median roadway deaths. In 2006, only two cross-median fatalities occurred on Interstate 70, a staggering 92 percent decrease.