Inflation that can save lives

ASEE Prism, Sep 2000

Each year, on average, 40,000 Americans lose their lives in automobile accidents. But an engineer at the University of Wisconsin at Madison thinks he's figured out a new and novel way to cut that figure by 25 percent. Airbags.

What? you insist, there's nothing new about airbags. True, airbags within car interiors have become standard-issue. But Bin Ran, an assistant professor of civil and environmental engineering, has patented a system that would also deploy airbags on the outside of cars seconds before serious collisions. The bags would buffer a car and ease any impacts, and could reduce the force of a collision between two bag-equipped cars by two thirds, Ran estimates. Moreover, exterior bags would also likely cut deaths among pedestrians and bicyclists hit by cars.

The technology for such a system already exists, Ran says. "It's very cost-effective," he adds, because the radar detection systems needed are already in use in some luxury cars. "The major additional expense would be the bags themselves--they'd have to be bigger and tougher than those used inside cars." Ran says the detectors can be fine-tuned to differentiate between, say, a scrap of blowing paper and a tree (or another vehicle), and to know whether an impact would be more than 5 m.p.h. Ran envisions installing exterior bags on the sides, fronts, and backs of cars.

He's ready to build a prototype, but has yet to receive the $500,000 he needs to proceed (that hefty sum includes the cost of crashing the prototype car). Still, he says, automakers from around the world have expressed interest, particularly those in Europe, and he's confident he'll eventually sell the concept. But don't expect to see outside airbags any time soon. Ran estimates it would take a manufacturer about five years to bring cars with exterior airbags into production.