Safer Roads
by Lauren Whisenhunt
CBS 42 News
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Most drivers don't even notice the roadside barriers, used to prevent cars from running off the road. But sometimes, barriers become part of the accident.
With some of these larger vehicles on the roadways, they are more susceptible to overriding these barriers or rolling over when they impact these barriers.
Barriers are tested for safety before they're put on roads. But costly, traditional crash tests offer limited information.
Now, mechanical engineers are crashing vehicles the modern way, using 3-D computer simulations -- giving better crash details to help design better barriers. Engineers have found that they can get much more information from the computer simulation.
Computer software is used to create 3-D models of vehicles and barriers. Then, a crash test is run that can be viewed from multiple angles. Vehicle parts can be removed to get an inside look at damage. Computers show what happens when cars and barriers collide, resulting in new, improved barrier designs.
The height of the barriers has increased. Now, the new barriers are typically higher than what it has been before.
Higher barriers improve safety for bigger vehicles and all vehicles in between.
Mechanical engineers try to find out the weakness of the barrier and to try to improve that weakness of the barrier through 3-D computer simulations.
Using virtual reality, researchers are also studying potential falls from ladders, with the goal of improving ladder design.
Redesigning Cars: Cars with crumple zones act more like springs being compressed against the wall, resulting in a cushioning effect, slowing the time it takes for the car to come to a complete stop and spreading the force over a longer period of time, with less potential for injury. As the car strikes the wall, the front crushes together like an accordion, absorbing the impact and allowing the middle and rear of the car to continue in motion for a short time. By making the time of impact one-tenth of a second longer, engineers can reduce the crash force by 20 times.
Risks of Speeding: Almost everyone goes a few miles over the speed limit when driving, but recent studies indicate that even a small increase over the legal limit can greatly increase the risk of an accident. Using data from actual road crashes, scientists at the
University of
Adelaide in found the risk of a car crash hospitalizing or killing people doubled for every five km/h above 60 km/h. For example, a car traveling 65 km/h was twice as likely to be involved in a serious or fatal crash, while one traveling at 70 km/h had a risk four times as high. Part of that reason is a driver has less time to react. On average, drivers react in 1.5 seconds. Someone who is drunk or distracted by loud music or talking on a cell phone may take as long as three seconds to react. Also, the faster someone is traveling, the less time they have to react to a perceived danger.
On the Web:
http://www.ncac.gwu.edu/
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