DOTD Cable Barriers

Cable median barriers are a safety feature designed to deflect a vehicle that enters the median, keeping it from potentially crossing over into opposing traffic lanes. They are designed to absorb the impact of the collision and hold a vehicle in the median, not pushing the vehicle back into traffic. Cable median barriers are an innovative and usually a cost-effective solution to prevent head-on collisions that potentially result in fatalities.

As of February 2022, DOTD has installed approximately 720 miles of cable barriers throughout the state at an investment of approximately $124 million. Cable barriers are currently located along the following corridors:

• I-10: East Baton Rouge, St. John, Ascension, St. James, Orleans, Jefferson, West Baton Rouge, Iberville, Calcasieu, Jefferson Davis, St. Tammany, Lafayette, and Acadiana Parishes
• I-12: St. Tammany, Tangipahoa, and Livingston Parishes
• I-20: Bossier, Webster, Caddo Bienville, Lincoln, Ouachita, Madison and Richland Parishes
• I-310: St. Charles parish
• I-55: Tangipahoa parish
• I-610: Orleans parish
• I-59: St. Tammany parish
• I-49: Caddo, Desoto, Avoyelles, Evangeline and Rapides Parishes
• I-220: Caddo and Bossier parishes
• LA 8: Vernon parish
• LA 3132: Caddo Parish
• US 167: Rapides Parish
• US 90: Assumption, Lafourche, Terrebonne, and St. Mary Parishes

There are currently another 15 miles under construction along the I-210 and I-10corridors. DOTD’s goal is to complete the installation of cable median barriers along the state’s rural interstate systems where feasible by the end of 2024.

In the end, nearly 735 miles of cable barriers will be installed across the state. To accomplish this goal, DOTD is using a combination of federal and state funding, with the majority being federal funding.

HISTORY OF CABLE BARRIERS IN LOUISIANA

Although cable barriers have been used since the 1960’s, it was not until the 1980’s that some state DOTs started to implement a modified cable rail as a median barrier. In Louisiana, the use of cable barriers was first explored after a resolution was passed in the 2006 legislative session to look into the feasibility of installing this safety feature. As part of the pilot study, the first two areas to receive cable median barriers were along the entire length of I-12 in St. Tammany Parish (32 miles) and along the entire length of I-10 in St. James Parish (6.8 miles). Project costs were $5.3 million and $1.3 million, respectively. I-10 barriers were completed in late 2008, and I-12 barriers were completed in the fall of 2009.

Due to the success of these pilot projects, DOTD developed a cable median barrier program to systemically install cable median barriers on rural and high speed, fully controlled-access facilities where feasible, or at site-specific locations were warranted based on crash data.

Based on data from 2009 to 2013 following the first round of cable median barrier installations, there has been a 33% reduction in cross-median crashes for these segments. In terms of severity, cable median barriers have reduced fatal and serious-injury crashes by almost 30% and 20% respectiA more recent research study was conducted through Louisiana Transportation Research Center, which evaluated the effectiveness of cable median barriers using data through 2020. This study concluded that cable median barriers can effectively improve interstate safety in the following cases:

• Reducing all fatal and serious injury crashes involving cross-median vehicles by 100%;
• Significantly reducing moderate-injury, possible injury, and property damage only crashes (71%, 81%, and 41% respectively) for cross median vehicles;
• Significantly reducing median related fatal, serious injury, and moderate injury crashes (58%, 13%, and 19% respectively); and
• Reducing 88% of head-on crashes involving cross median vehicles.

The cable barrier system is a testament to DOTD’s commitment to improving safety on Louisiana’s roadways through a safe system approach.