Archive for Sunday, December 28, 2008

KDOT mulls guard cables on highways

December 28, 2008


— Kansas transportation officials are trying to decide whether installing guard cables in highway medians would be worth the cost and actually make it safer to drive in the state.

A study conducted for the Kansas Department of Transportation concludes that the cables — already in place in 25 other states, including Missouri — can help save lives in some instances, but might not be all that helpful in others.

“We’ve always known you could reduce the potential for fatalities” with guard cables, said Jim Brewer, engineering manager in KDOT’s design bureau. “But if you increase the potential for injury and property damage … then you may not have improved the system.”

According to the study, conducted by a national traffic safety expert at the University of Nebraska, the cables work best on highways with narrow medians and high traffic.

But they can pose a risk on highways with wide medians and low traffic — characteristics of many Kansas roads.

“The cable is always there, no matter how light the traffic volume gets,” said Dean Sicking, the Nebraska expert who directs the university’s Midwest Roadside Safety Facility. “If you get to the middle of the median, you’re going to hit that cable.

“But as long as the volume goes down, the risk of hitting somebody in the opposing lane drops off real fast.”

Kansas started looking into the cables in the summer of 2007 when five people were killed in crossover crashes, including three in a collision on Interstate 435 in Lenexa.

Sicking’s study was meant to help the state choose where guard cables could be installed without paying the $100,000 per mile cost in places where they aren’t needed.

From 2002 to 2006, Kansas averaged 5.6 highway deaths per year caused by crossover accidents.

That’s not a big number compared with the average of 270 fatalities in all other crashes, the study said.

KDOT officials hope to decide by March whether to install the cables.

Missouri has had them on its highway medians since 1999, with 500 miles of cables including 75 miles in the Kansas City area.

State highway officials say the cables have reduced traffic fatality rates.

But Missouri’s interstate highways have narrower medians — most about 40 feet wide — with steeper embankments than in Kansas, where medians on Interstate 70 tend to be wider and flatter, giving drivers a better chance to recover if they run off the road.


Rashamon 9 years, 6 months ago

Dude. $100,000 a mile? Somebody is lining their pockets.

waddles4 9 years, 6 months ago

KDOT says that it has KNOWN that it could reduce the potential for fatalities but it may increase the potential for injuries or property damage? Are you serious? I think I would rather have my loved one injured and alive then dead on a highway because someone crossed over the median. Install the guard cables and save a life.

Fort_Aubrey 9 years, 6 months ago

Doesn't anyone remember the family of a young lady (Salina?) who was maimed in an accident involving guardrails and whose family conducted a campaign against these kinds of traffic barriers?

Confrontation 9 years, 6 months ago

Ban cell phone use while driving, and you'll see the number of accidents greatly decrease.

Gina Bailey-Carbaugh 9 years, 6 months ago

Fort, I believe the accident you are referring to involved a guard rail, not cable. And, since then, the guard rails have been revised with those big square pieces to keep the rail from impaling the car and passengers.Having seen one too many deaths from a cross-over head on collision, I say, Put the cable up already!

gccs14r 9 years, 6 months ago

CalTrans thoroughly discredited cable barriers in a study they did. They're ineffective and dangerous, especially to motorcyclists. The best divider system is the Jersey barrier.

KS 9 years, 6 months ago

Rashamon - I agree! Someone is linning a pocket. Typical when the taxpayer is footing the bill. These cables are a waste of money. They WILL NOT stop a truck from crossing.Confrontation - Ban cell phones? While you are at it, ban kids in the back seat from whinning, ban radio tunning, ban talking to a passenger, ban drinking a coke while driving. Get a life. There are already laws on the books that take care of this. It is called inattentive driving. I say ban driving in the left lane on a four lane road. The last time some people have looked out of their read view mirror was when they backed out of their driveway, maybe!

terrapin2 9 years, 5 months ago

I don't know what kind of cost you would expect to incur but 5,280 ft of cable X 2 (both sides of the median) = 10,560 ft of cable for every mile. And that's thick high-strength corrosion-resistant steel cable. So if it costs $5/ft that's $52,800/mile plus the cost of the posts & hardware on top of the cost to install it all. So if you still think $100K/mile is so outrageous I'd like to see you find someone who can do it for less!

mizzou_jayhawk 9 years, 5 months ago

the median guard cable SAVES lives - that's the bottom line. The best place to start would be K-10; that's one place the volume would likely be sufficiently high enough. KS- Yes, the cables will stop a loaded tractor trailer, I've seen several stopped by the cables in Missouri along I-70 and have the pictures to prove it. Here's a video posted by MoDOT on their YouTube channel that shows how the cables cradle and catch an errant vehicle: here's the MoDOT cable specs: one drawback as mentioned by gccs14r is that motorcyclists have to put their bike down otherwise it works like a cheese slicer, but errant motorcyclists require much less lateral distance to regain control. The only other down side is that mowing becomes slightly more difficult as you have to mow around the cable barrier, and possibly at times requires several folks with weed-eaters to cut down the grass.

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