For Kristina Nickelson, guard cable meant the difference between safety and tragedy during an accident earlier this winter. Nickelson was traveling at around 35 mph when her Jeep slid off the road and into the guard cable lining the median. The safety cable prevented Nickelson from crossing into oncoming traffic.
“I was on I-70, just leaving Columbia when I hit some black ice,” Nickelson said. Nickelson commutes from Columbia to her job in Jefferson City as a secretary in Rep. Rod Jetton’s office.
Head-on collisions are some of the most severe and deadly crashes on our roadways.
Between 1996 and 2004, more than 378 people were killed and 2,256 injured in crossover crashes on Interstates 44, 55, and 70. Fortunately, median guard cables significantly reduce the number and severity of crossover crashes.
Cross-median crashes occur when a vehicle crosses the median and enters the opposing traffic lane. These types of crashes tend to be very severe because vehicles hit head-on at high speeds. The crashes are most frequent on highways with high-traffic volumes and narrow medians; and often occur when drivers fall asleep at the wheel or fail to slow down during bad weather.
The most common types of interstate median barriers are guard cables, concrete barriers and guardrails. Missouri uses guard cable most often because the cost of installation is 40 percent less than guardrail and 80 percent less than concrete barrier. Additionally, guard cables produce less damage to vehicles and their occupants because of their flexible nature.
“Median guard cables are effective in reducing the number of cross-median crashes both disabling and fatal and they are cost-effective,” said MoDOT State Traffic Engineer Eileen Rackers. “The cables are hit more often, but more lives are being saved.”
MoDOT began installing guard cable in 2002 and has already installed or is currently completing approximately 160 miles of guard cable on highways throughout the state. Several projects are planned over the next two years to add more than 430 additional miles of guard cable barriers on interstate highways.
To date, all guard cables installed in Missouri were made with low-tension steel cables. The low-tension cable barriers cost about $60,000 per mile to install and approximately $10,000 a year to maintain. Low-tension guard cable must be repaired after each hit to maintain effectiveness. Most of the money comes through federal safety funding.
Nikelson, for one, believes the guard cable is extremely important to Missouri motorists.
“I could feel it when the guard cable hit my car. It dented up the back of my jeep,” Nickelson said. “But, the damage was nothing like what would have happened if it hadn’t been there.”
MoDOT is also considering experimenting with a new high-tension design on Interstate 29 from Buchanan to Platte counties. The high-tension design usually remains effective even after an impact from an automobile, unlike the low-tension design. The posts supporting the high-tension cables are spaced closer together for more support. The high-tension cable costs 30 percent more per mile to install, but far less to maintain because the posts can easily be replaced if damaged.
