Guard cables to help prevent I-70 crossovers

Thursday, September 23, 2004 | 12:00 a.m. CDT; updated 6:17 p.m. CDT, Friday, July 18, 2008

With 22 traffic deaths for every 100,000 people, Missouri is in a four-way tie for the ninth-highest traffic death rate in the country, according to a recent report released by the National Highway Traffic Safety Administration. Interstate 70 has a reputation for being particularly dangerous, especially because of the state’s high rate of crossover accidents, which occur when a vehicle crosses the median into opposing traffic.

As of July 15, the most recent statistics available, there have been 50 crossover accidents on I-70 across Boone and Callaway Counties, three of which have ended in fatalities. In 2003, there were a total of 76 crossover accidents in the two counties, resulting in eight deaths. The Missouri Highways and Transportation Department is hoping to greatly reduce those numbers with its guard cable installation project, which will eventually extend median guard cable barriers across the state.

Crews are currently working to install guard cables in Boone and Callaway counties, extending one mile into Montgomery County. When the project is completed, the Highway Department will seek bids to continue the guard cables west from Columbia towards Kansas City.

“We are slowly but surely making contracts throughout the state,” said Chuck Sullivan, Central Area engineer with the department. “At the completion of this project guard cables will be continuous from St. Louis to Boone County, and next year they are bidding a contract from Boone County to Cooper County.”

Guard cables were first installed in St. Louis due to the high volume of traffic there and the inclement weather, two factors that contribute to the high number of crossovers.

“The number of crossover accidents has increased as the traffic volume increases,” Sullivan said. “And I-70 is one of the oldest highways in the nation and it is deteriorating.”

The department studied guard cables in other states as a possible solution to the crossover problem.

“We looked at the cables in North Carolina where they have proven cable can minimize the amount of vehicles that pass through the median, which is the overall goal,” said John Miller of the department. “The numbers we have are not foolproof, but we found about a 90 percent success rate based on vehicles that were not able to pass through to other side.”

Miller said cables seemed the ideal solution as opposed to concrete barriers because they can cover a lot of miles and do a better job of keeping cars in the median than concrete, which tends to redirect the car back into traffic.

The cables have been tested and meet National Cooperative Highway Research Program standards, which is required to get money from the Federal Highway Safety Commission. The system uses a three strand wire cable which is approximately three-quarters of an inch in diameter. The cables work based on tension. A “deadman,” or chunk of concrete, is on each end, and brackets connect the cables to the posts. There are springs on each end to keep the cable tight and straight. The cables will deflect the car and then wrap it back into the median, keeping cars from bouncing out into traffic. While both Sullivan and Miller noted that the cables are designed for automobiles and not large trucks, Miller said the cables are very strong.

“Even 18-wheelers have been stopped, retained and kept in the median,” he said.

Installing the cables is a multi-phase project. First, a rock trench and weed barrier is put in, then posts will be installed and the wire will be strung.

The rock trench is completed and crews are installing posts in eastern Callaway County. They hope to complete the 37-mile project by July. The total cost of the project is about $3 million.

The money for the project is from the Federal Highway Safety Commission. Missouri gets 90 cents back for every dollar that it gives to the Highway Safety Commission for safety projects such as this one.

Regardless of the cost, Sullivan and Miller agree it is important to improve highway safety.

“I honestly support this project because the goal is to reduce the severity and the number of crashes,” Miller said.

Like what you see here? Become a member.

Show Me the Errors (What's this?)

Report corrections or additions here. Leave comments below here.

You must be logged in to participate in the Show Me the Errors contest.


Leave a comment

Speak up and join the conversation! Make sure to follow the guidelines outlined below and register with our site. You must be logged in to comment. (Our full comment policy is here.)

  • Don't use obscene, profane or vulgar language.
  • Don't use language that makes personal attacks on fellow commenters or discriminates based on race, religion, gender or ethnicity.
  • Use your real first and last name when registering on the website. It will be published with every comment. (Read why we ask for that here.)
  • Don’t solicit or promote businesses.

We are not able to monitor every comment that comes through. If you see something objectionable, please click the "Report comment" link.

You must be logged in to comment.

Forget your password?

Don't have an account? Register here.