You've seen them while driving on interstates in most places around the country, and you probably didn't take much notice.  But these structures have saved countless lives. They're highway cable barriers.

Some of the most catastrophic crashes in history have been caused when a car or truck crosses over into oncoming traffic.  Cable barriers are installed somewhere on the dividing line between opposing lanes.  While you'll sometimes see them installed on the asphalt between lanes, they are primarily used on divided highways and are installed in the middle of the median.

Although they've been around since the 1960's, cable barriers became prevalent in the 1990's because they are much cheaper to maintain than their concrete and/or steel counterparts.

This week, the Louisiana Department of Transportation and Development (DOTD) is beginning a $5.7 million construction project on I-49.  DOTD will be installing cable barriers in the median along a 41-mile stretch of the interstate through Caddo and DeSoto Parishes.  Construction will start at the Inner Loop interchange in Shreveport, and continue all the way through Desoto Parish to the Natchitoches Parish line.  If you travel along that route you will start to see construction signs popping up this week.