You've driven by them countless times and probably never given them a second thought.
MoDOT says highway cable barriers are saving lives, but at what cost?
We asked transportation officials how much it's costing taxpayers, and if it's worth it.
There are now 550 miles of cable barriers protecting drivers from crossover accidents on Missouri interstates and highways.
MoDOT said Missouri is trying to lead the way in roadway safety.
John Miller, Traffic Safety Engineer said, "We think we've applied them appropriately in our state, they can save lives".
Last year on I-70 alone there were nearly 700 hits to the median cable, and MoDOT says each one is a potential life saved.
But those lives aren't coming cheap to taxpayers.
On Interstate 70 between St. Louis and Kansas City, MoDOT spent between $18 million and $20 million to install the barriers and then an additional $2 million dollars per year on maintenance.
"Obviously everybody is worth a lot to society, but we have to look at the cost benefit to a lot of our projects and when we do a lot of that, and look at safety projects in general, we try to value a life at a $4 million to $5 million range. So if you think about that and I tell you we've saved hundreds of lives that's millions of dollars we've saved in the state of Missouri." Miller told us.
Gail Fields credits the barriers with saving her life when she and her husband were traveling I-44 on their way to Arkansas, "That van that we met on the other side of the freeway sliding into the ditch and hitting it and reflecting up into traffic instead of rolling over our car has changed our whole perspective." Fields said.
Jim Day and his wife Tonya are from New Florence.
They say they were saved by the cables on I-70 when a tractor-trailer came lost control, "We kind of both braced for it and as soon as it hit the cables, the cables just stopped it dead in it's tracks. It saved a lot of lives that day not only us and that truck driver but of course there were cars behind usâ??.
MoDOT says there is an average of one cross median fatality every year compared to 18 to 24 fatalities before the barrier cables.
Since 2001 about 260 lives have been saved throughout the state, at 4.5 million dollars per life, that's more than a billion dollars.