Recent studies by the Texas Transportation Institute (TTI) and the Texas Department of Transportation (TxDOT) have determined that high-tension cable barriers constructed along 700 miles of Texas roadways are doing their job.

 

Cable barriers, sometimes referred to as guard cable, are a type of roadside or median barrier and consist of steel wire ropes mounted on weak posts.

 

Because these barriers are relatively inexpensive to install, and are very effective at capturing vehicles, their use is becoming increasingly common in the United States.

 

After examining the effectiveness of the barriers in terms of maintenance costs and safety, the TxDOT study found that 18 fatalities and 26 injuries were prevented last year.

 

These findings are similar to studies conducted last year which showed a drop in fatalities from 52 to just one. The studies focused on Texas medians that had cable barriers in place for at least 12 months.

 

Cable barriers are designed to keep vehicles from crossing into oncoming lanes of traffic. These crossovers often result in head-on collisions. Also similar to most roadside barriers, cable barriers function by capturing and/or redirecting a vehicle.

 

The most popular use of the cable barrier system occurs in the medians of divided highways. Given the opposing directions of traffic on divided highways, cross median crashes are particularly severe. While the width of a median plays a large role in the occurrence of these crashes, increased width alone does not eliminate them and quite often, the median must be shielded with a barrier. Cable barriers provide a cost-effective solution to the shielding issue.

 

"If you cross the median, chances are good that the resulting crash will cause a fatality or incapacitating injury because they usually occur at high speeds," explained Scott Cooner, a Texas Transportation Institute (TTI) research engineer devising a cable barrier maintenance manual for TxDOT.

 

"The studies make it clear that cable barriers are keeping people from crossing the media...and they are saving lives,” added Cooner.

 

The cable systems are a cost-friendly alternative to concrete barriers, costing approximately one-third of their cost.

 

However, the study discovered that maintenance costs for the cable barriers are considerably higher than costs to repair concrete barriers.

 

"That seems to be the only disadvantage," Cooner said. "Over a 15-year lifespan of the cables, the maintenance costs will be higher but still less expensive overall compared to their concrete counterparts."

 

Since 2001, TTI has been involved in the crash testing of end terminals and components for cable barriers. Cable barriers have become common fixtures along the nation's highway system.