Cables are highway safety net

It was seven years ago, but Renee Thorson's memory of the day is still vivid.

Her husband, Stephen Thorson, was at the wheel of their Dodge Durango on Interstate 80, eastbound near Stuart, Iowa, on Oct. 12, 2003.

“Steve goes ‘Oh, my God!' And when I looked up, there was a car sideways — a red car sideways in the median — and it came after us. It was flying at us. It was airborne.”

The Thorsons survived but three people did not, including Jennie Guyer, the daughter of Renee Thorson's cousin.

Seven years later, vehicles still lurch across medians and slam into oncoming traffic. In the span of two weeks this month, 12 people died on Iowa Interstates in three accidents when vehicles crossed into oncoming traffic.

Such crashes aren't the most numerous — Interstates are widely considered the safest roads in America — but they can be spectacularly deadly when they happen.

A Federal Highway Administration study of deaths in Iowa in the 1990s showed that only 2.4 percent of all Interstate crashes were cross-median collisions, yet those resulted in 32.7 percent of all Interstate fatalities in the state.

One solution being tried in Iowa and elsewhere is cable median barriers. The cable barriers are in place along Interstate 80 in Council Bluffs and on U.S. Highway 75 in Bellevue. Iowa has plans to install more. Nebraska does not, at this time.

The barriers are less expensive than the concrete barriers used to separate traffic on urban freeways in Des Moines and Omaha.

And they are effective: Missouri has seen crossover crashes plummet since it installed about 600 miles of cable along its busiest highways.

Cable barriers prevent 90 percent to 95 percent of cross-median crashes, said Dean Sicking, a professor of civil engineering at the University of Nebraska-Lincoln who helped develop cable barrier systems for Missouri, Kansas and Arizona.

“It does not prevent them all, but it does cut them down dramatically,” said Sicking, who is director of the Midwest Roadside Safety Facility at UNL.

Cable median barriers generally rise about 4 feet off the ground and are made up of three taut horizontal cables. The cables are designed to catch a vehicle and prevent it from crossing into oncoming traffic, even if some of the support poles give way.

The poles supporting the cables can easily and inexpensively be replaced. “They're dirt cheap,” Sicking said.

Interstate 70 between Kansas City and St. Louis had one crossover fatality in 2008, compared with 24 in 2002, when only a few medians had barriers, according to the Missouri Department of Transportation.

“Our best estimate is that we save about 45 lives a year with the amount of cable we have out there now,” said Jon Nelson, a senior traffic studies specialist with the department. “We're very pleased, obviously, with the results. … It's been a big success.”

Iowa began installing cable barriers in 2004. Most of the 25-mile stretch of Interstate 35 from Ames to Ankeny, just north of Des Moines, has barriers. In 2007, while inspecting I-35 near Ankeny, engineers found several places where vehicles apparently had crashed into the cable barriers but did not break through into oncoming traffic.

“We had several crashes where someone went into the barrier and did not collide with any vehicles, or they had a secondary collision with a vehicle going in the same direction,” said Scott Falb, a driver safety specialist with the Iowa Department of Transportation. “So that saved some very serious injuries.”

It costs Missouri $105,000 to $110,000 to line one mile of highway median with cable. Iowa puts its costs lower: about $65,000 per mile.

Iowa has no immediate plans to line all of its Interstates with cable. The state expects to apply $4 million of its $15 million in Highway Safety Improvement Program funds in 2011 to installing cable barriers. The rest of the money will go to more urgent projects on other roads, officials said.

“We don't have a plan to just go out there and blanket the whole Interstate,” said Troy Jerman, a senior transportation engineer in the Iowa Office of Traffic and Safety. “We'll evaluate the data.”

One stretch of Iowa Interstate that may get a fresh look is I-80 in Jasper County, east of Des Moines.

So far this month, that stretch has seen three crossover accidents, including one that killed seven people and another that severely injured four. Another such crash last Monday killed a 19-year-old woman from Colfax, Iowa.

The crash that killed four motorcyclists on Interstate 29 near Little Sioux, Iowa, on Aug. 9 occurred in a construction zone that had southbound traffic diverted to a single lane on the northbound side of the Interstate. The two lanes were separated by a double yellow line and 4-foot-high orange-and-white plastic sticks. Cable barriers aren't used when there is no sizable median in a work zone.

The Iowa Department of Transportation has scheduled cable barrier installation on I-80 east of Des Moines in Poweshiek, Iowa, Johnson, Cedar and Scott Counties.

In Nebraska, state roadway design engineer Jim Knott said two words when asked how the state prevents crossover crashes: “Wide medians.”

Older stretches of Nebraska Interstate have 60-foot-wide medians. The median on the reconstructed six-lane stretch of I-80 between Omaha and Lincoln will be 76 to 88 feet wide.

“We have not experienced any significant location where we are having a large number of cross-median crashes,” Knott said.

When a problem with accidents was noticed along a 1.2-mile part of U.S. Highway 75 in Bellevue, a cable median barrier was installed and cross-median crashes were reduced. There were none there during the first five months of 2010, according to the Nebraska Department of Roads.

“In places where we've used it, it's working well,” Knott said. “You can never tell how many crashes it actually prevented.”

On I-80 in Nebraska during the first five months of 2010, roughly 20 crashes could be described as cross-median. One of was fatal.

Fred Zwonechek, administrator of the Nebraska Office of Highway Safety, described cross-median crashes in Nebraska as “rare.” He said a total of 20 crashes in five months along more than 450 miles of Interstate is not many.

“Here, we are fortunate because they are fairly random and there generally isn't a place where we have a lot of them concentrated together,” he said.

Without a pattern indicating a problem site, he said, where do you put the cable?

Much of the money the state has to spend on highway safety can be better spent on roadways that are less safe, Zwonechek said.

For one Nebraskan, though, wide medians weren't enough.

Lori Jones doesn't remember the May 2002 crash that broke her bones, hammered her brain and put the former statistical analyst for the Nebraska Department of Revenue on disability.

Here's what the State Patrol, her doctors and her family have told her: She was westbound on I-80 near Greenwood, Neb., when a car went out of control after hitting a wheel that fell from a truck. The out-of-control car veered across the median and slammed into Jones' vehicle.

She does remember the months of rehabilitation, the frustrating hours she can no longer fill with work and the complicated numbers she can no longer crunch.

“Why did this happen to me when it could have been prevented?” she said. “Extra width means 2 seconds, essentially. And 2 seconds means nothing.”

Renee Thorson also sees a need for more median barriers.

“I would be very supportive of anything that would keep cars going in one direction and from going into the other lane,” she said.

She can still recall the details of the seemingly slow-motion collision of vehicles in her accident. Sheet metal crumpling. Glass shattering.

“I remember thinking ‘God, it's beautiful,' because it looked like diamonds,” Thorson said.

Unlike Jones, the Thorsons have continued working at their business in Austin, Minn., where they help the developmentally disabled, chronically mentally ill and elderly.

But the crash is still with them. Steve Thorson will soon go in for a crash-related hip and knee replacement. He sometimes needs a cane to walk. The diminished mobility is tough.

“He doesn't complain often, but when he does, we just kind of look at each other” — Renee Thorson paused and took a deep breath — “and say ‘Well, we're alive.' ”

Contact the writer:

444-3106, andrew.nelson@owh.com

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