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Safety officials seek ways to stop highway accidents
Posted By admin On January 18, 2012 @ 9:03 pm In | Comments Disabled
Published on Jan. 18, 2012
On Nov. 23, 2007, Kate Zoromski, 16, was traveling south on Interstate 43 to her home in Grafton, Wis., when her car drifted out of the travel lane and into the median.
A cable barrier was in place to stop the vehicle, but it slipped underneath into oncoming traffic. The car collided with an SUV, killing Zoromski and one of her friends instantly. A third person died a week later from head injuries sustained in the crash.
U.S. traffic fatalities have been dropping steadily over the past decade, according to the National Highway Traffic Safety Administration, but the numbers are still staggering: More than 32,700 people died in traffic accidents in 2010. Many of them were young.
In fact, motor vehicle accidents are the leading cause of accidental death for Americans under the age of 34 and the 10th leading cause of death for all ages, according to the Centers for Disease Control and Prevention.
Safety engineers are doing what they can to change those statistics, using three very different engineering solutions that alert drivers to danger, slow down traffic and physically impede vehicles from leaving the roadway. All three have been shown to reduce the likelihood of accidents, but as Kate Zoromski’s family discovered, they do not always prevent them.
One of the most nagging safety problems is on rural highways, partly due to the sheer number of them and partly because of engineering.
Many narrow two-lane highways were engineered decades ago, and are substandard by today’s standards. Tight, frequent turns, higher speed limits, wildlife crossing roads and fatigue all make rural roads more dangerous than modern urban highways, according to the National Highway Transportation Safety Administration.
Exactly how dangerous is open to interpretation, but official estimates put the level of danger on rural roads as double to triple that of urban roads.
In 2005, NHTSA reported that the rural fatality rate was triple the urban fatality rate on roads. The U.S. Census estimates that from 2000 to 2009, rural traffic deaths accounted for 57 percent of total traffic fatalities, according to federal crash data – a far greater proportion than the 23 percent of the country’s population that lives in rural areas.
Driving habits are partly to blame. Safety experts agree that people tend to drive differently on rural roads than urban ones.
Urban roads carry more lanes and traffic, honing the drivers’ senses because there are more things happening around them, said Insurance Institute for Highway Safety vice president Russ Rader. Rural roads typically are less busy but aren’t as straight, and drivers may not be as alert.
“Rural roads lull drivers into a false sense of complacency because they are monotonous and can stretch in one direction for long periods of time with little to no traffic,” Rader said. “Drivers feel like they are safe because of how inactive the roadway is, and they lower their guard.”
To make rural roads safer, highway engineers began putting in rumble strips beginning in 1952. A machine cuts notches, or rumble strips, into the pavement that send an unmistakable shudder through a vehicle that is straying from the travel lane.
Rumble strips are cost effective and require no major reconstruction of the road. The Texas Transportation Institute found rumble strips cost about 25 cents per foot to install.
And they seem to be effective, cutting in half the number of crashes in which a vehicle drifts onto the shoulder, the Texas Institute found. When the notches are cut in the middle of a two-lane or four-lane highway with no median present, crossover crashes fall 30 percent to 40 percent, according to the Federal Highway Administration.
“Rumble strips are a good treatment for rural highways where redesigning an entire stretch of highway is too expensive,” said Ray Krammes, a senior highway research engineer with the Federal Highway Administration, an agency within the U.S. Department of Transportation that supports state and local governments in the design, construction and maintenance of highways.
If rumble strips are the low-cost workhorse engineering treatment for rural highways, roundabouts are the boutique innovation for cities.
In cities, crashes are more attributable to dense traffic so safety solutions tend to focus on ways to control traffic. Roundabouts are one such method.
A type of circular junction in which traffic travels in one direction around a central island as vehicles enter and exit, roundabouts have been widely used in Europe, where they are hailed as effective in reducing traffic accident. They are beginning to gain traction in the U.S.
At first, small roundabouts began cropping up in residential areas as an alternative to speed humps. Then, they began replacing big intersections with traffic lights; they are now being introduced on freeway interchanges.
Ten years ago, there were roughly 50 roundabouts in the nation. Today, there are more than 2,000. Converting a two-way stop, four-way stop or signalized intersection to a roundabout reduces fatalities by 75 percent and overall injury by 30 percent, the Federal Highway Administration says.
That’s because roundabouts slow traffic to a speed where deadly collisions are less likely. Collisions typically occur on the rear or side of vehicles and when cars waiting for traffic move slower than 25 mph, Krammes said.
So rather than high-speed T-bone crashes at traffic lights, officials settle for more common fender-bender accidents. They may cause a body-shop bill, but rarely cost a human life.
A two-lane roundabout costs roughly $330,000, while a typical intersection with traffic signals and turn lanes costs about $450,000, according to a study done by the Washington State Department of Transportation. Additionally, roundabouts do not require electrical maintenance that signalized intersections do.
If roundabouts are the higher-cost, generally effective treatment for cities and rumble strips the cheap but highly effective design on rural roads, cable median barriers offer safety on the cheap for divided highways everywhere.
But while cable median barriers are one of the more popular roadway safety improvements, highway engineers and safety advocates heatedly debate their effectiveness.
In the past seven years, 20,000 cable median barriers have been installed across the country. Part of the reason is cost: A cable median barrier costs $12 to $15 per square foot compared to concrete median barrier’s cost of about $80 per square foot.
“Cable median barriers are taking off because of how cost effective they are and the positive returns you get for such a low installation price,” said Cody Stolle, a graduate student the University of Nebraska-Lincoln and engineer at its Midwest Roadside Safety Facility.
Supporters say the barriers produce a 95 percent reduction in median crossover accidents, but the remaining five percent result in horrendous, often fatal accidents. When a cable barrier failure occurs and an accident is the result, it often involves two or more vehicles colliding head-on at high speeds, as did the one involving young Kate Zoromoski five years ago.
Zoromski was eager for a hot meal after cheerleading practice. She merged onto I-43 and headed for the nearest International House of Pancakes, 10 miles away, as she had countless times before.
Two miles later, Zoromksi lost control of her Mazda sedan and slid beneath the cable median barrier into oncoming traffic. The crash killed her, two of her passengers and left one survivor facing a grueling recovery. The crash resulted in a pileup that caused four additional injuries.
The town of Grafton is a church-bound community of 12,000 that felt the ripple effect of the accident far beyond the front page of the newspaper. The magnitude of grief was palpable – as was the level of incredulity.
People began to question the integrity of a cable barrier that was installed a year prior to the accident with the price tag of $525,000.
“How there can by a safety measure in place that allows a car to pass underneath the barrier is beyond me,” said Mark Zoromski, Kate’s father. “The physics of it just don’t make sense to me. Breaking through the barrier – well, maybe. Passing under it… I can’t wrap my head around it.”
The Wisconsin State Patrol and the Wisconsin Department of Transportation launched an investigation, ultimately blaming flaws in the engineering, design and construction of the cable median barrier.
The area’s deep freezes and quick thaws can saturate the ground with moisture. Ozaukee County officials admitted that the ground was soggy when they built the barrier, contrary to a Federal Highway Administration mandate green-lighting the project, which stated that the ground was secure and did not possess any alarming characteristics that would deter construction.
Despite the discrepancy, Mark Zoromski did not file a lawsuit. Instead, he has turned his focus to educating officials on cable barrier safety standards so another tragedy can be averted.
The barriers are designed to have no more than 21-inch gaps between each cable as well as from the ground to the lowest cable. Gaps in the I-43 barrier ranged from 24 to 33 inches, investigators found. The front bumper of Zorokowski’s Mazda was 21 inches high, allowing it to wedge underneath the cable with enough force to pass through.
Because posts were set 19 feet as opposed to 16 feet apart, the cables lacked proper tension to stop a car. The county also built a three-cable barrier, rather than a four-cable system, which is scientifically stronger, according to the State Patrol Accident Reconstruction Report.
Still, engineers for the state of Washington concluded that the cable median barriers, when properly installed, are better than the alternatives. They analyzed 11,457 median barrier collisions within the state from 1999 to 2004 and found that cable median barrier crashes recorded a 16 percent chance of injury or death compared to concrete median barrier’s 40 percent. Scientifically, cable median barriers are more effective.
Mark Zoromski finds no solace in the statistics.
“I miss (Kate) every day,” he said. “Coping is painful. I cry all the time. I really miss her. To think that such a simple fix as having a fourth cable or lowering the height of the lowest cable could have saved her kills me inside.”
Three and a half years later, a fourth cable median barrier has not been added to the stretch of barriers where Zoromski and her two friends died.
The state was supposed to test the effectiveness of installing a fourth cable median barrier in 2009 to determine whether it would be worth the price to install. But the test costs $50,000, and each time it has been suggested, the state has been unable to come up with the money.
“Nobody has put a priority on improving this stretch of cable median barriers or making it a requirement that they have four (cables) to begin with,” Mark Zoromski said. “In the meantime, I pray it doesn’t happen again… to somebody else.”
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