Drive along the highway in Michigan, and you’ll see cable barriers in the grassy medians. They’ve been popping up more in the last 15 years.
WMUK listener Neil Lifson of Wayland Township wanted to know more about the barriers — he said he's done a lot of work on houses, and always tries to keep the maintenance as low as possible.
"I always wondered why it seems they set up these cable barriers. They’re creating a lot of maintenance issues,” Lifson said. "It seems kind of counterproductive and wasteful."
Other drivers have wondered if they’re safe and what they do to your car if you hit them. So we set out to find out more about cable median barriers, as they’re called.
A metal safety net
It turns out cable barriers first appeared along US highways in the 1960s. They’ve been appearing in Michigan since 2009.
Michigan Department Of Transportation spokesperson Nick Schirripa explained that there’s a key difference between the cable barriers and other barriers.
“As you can imagine, if you hit a steel guardrail or a concrete barrier at 70 miles an hour, the barrier is going to win every time. They are not very forgiving," Schirripa said.
But he said cable barriers are meant to give a little. They’re made with cable wire, and metal posts stuck into soft ground. Think of them like a sort of net made of metal.
“That cable gives a little. The posts are designed to be tear away. They're designed to just break off," Schirripa said.
Their goal: stop a high-speed vehicle from crossing the median into oncoming traffic while preventing fatal injuries all around, "if we have a little bit of give and we can slow you from 70 to 0 rather than stop you from 70 to 0."
Mowing and other maintenance
Question-asker Neil said it’s common for him to see broken cable barriers, and wondered how long it takes to repair them. Schirripa said repairs can be difficult in the winter.
“As soon as you pull one of those poles, it fills up with snow and ice," Schirripa said. "So, we've got to be careful when we do that. We might have to wait for a thaw in some cases."
And they might have to wait for a crew, since sometimes they’re too busy plowing.
MDOT also contracts with crews to mow the medians about three times a year. Neil wondered whether the department could cut down on mowing time by planting things like clover instead — which only grows a few inches tall and would require minimal mowing.
“I would think that if they’re going to put up the cable systems, they also have to put in low grass ground cover," Lifson said.
Schirripa said MDOT is working to plant more grass alternatives like wildflowers, sunflowers and more in areas all across the state. But he added that clover does not drain well enough for medians. Medians require a certain level of drainage to account for road runoff.
When repairs have to be done, Schirripa said the cost is fairly nominal at $170 a post with about 5 or 6 posts needing replacement on average. And the repair costs are often offset by the person who hit them — if you hit the median, the state will send you a bill.
“And that is not unusual. If you hit a stop sign or a road sign, if you hit a steel guard rail or a concrete barrier, and any of that needs to be replaced, if it is publicly owned, you will be responsible for paying the fee, not the taxpayers themselves.”
Are the safety nets safe?
According to Schirripa, when the barriers first appeared, people were worried about amputations. He said he knows only of one: a freak accident in which a woman lost her legs.
James Graham of Graham’s Towing and Recovery in Kalamazoo said that a few years ago, he helped clear a crash involving a semi-truck driver whose truck went through the cable barriers.
“It cut his leg off and it killed him," Graham said.
Schirripa emphasized that anecdotes like these are very rare. There are few reports, and no significant data that tracks these incidents. Schirripa also said cable barriers aren't rated for semi trucks or other large vehicles, though he pointed out that the barriers have stopped them on several occasions.
And Graham, who said he’s towed many vehicles that crashed into the barriers, still believes the benefits of the cable barriers far outweigh the risks.
“My opinion, of course, I’m not a traffic engineer, is they exist to save lives and they’re specifically designed to have a certain amount of stretch to them as opposed to a rigid barrier. So they’re more survivable if you hit them," Graham said.
Data overwhelmingly shows that a cable median barrier is much more likely to save your life than hurt you. One US Department of Transportation report found they reduce cross-median traffic deaths by 92 percent.
Graham added that in his experience, the most controversial aspect of the barriers is the potential to cause damage to a vehicle that slides into the median.
"f you're driving on the highway and you slide off into the ditch, you will most likely not have any body damage if the cable barrier is not there. But if the cable barrier is there, you'll sustain damage. Okay? And that I think is the most controversial key point is that people get mad and say, "Well, if those stupid cable barriers weren't there, I'd just had to pay a tow truck to get pulled out." And that'd be the end of that," Graham said.
But, he said that it's unlikely for a car to slide off the road if the vehicle is properly maintained and road safety laws are followed — and added that the barriers specifically exist to catch cars.
Future improvements ?
We circled back with Neil to see what he thought of his newfound knowledge of cable median barriers. He said he learned a lot – but he wonders if they could be made from material that doesn’t break as often.
“I understand catching the car without having fatalities — obviously that makes sense, I’m just wondering if there are other systems that would be requiring less maintenance," Lifson said.
Schirripa says if there is a better and more cost-effective alternative, MDOT is all ears.
