New York Times - Sunday 12 September 2004
Making Cars Safer for Pedestrians
By Jim Motavalli
|It is a dark, moonless night, and the jogger on the road is wearing dark clothing. You do not see him, but your car does.
Infrared cameras on your bumper identify his heat signature and send a signal to your car's computer. A warning sounds as the brakes are automatically applied. A heads-up display projects his image onto the windshield. Your safety belt tightens in anticipation of an impact. But with the car slowed to a crawl, the crash never comes and a tragedy is averted.
Such technology is not yet available on cars sold to the public, but it exists, thanks to research by automakers including Mercedes-Benz and Honda and by suppliers of safety technology including TRW, Siemens and Autoliv. The research has been conducted with some urgency, since manufacturers doing business in Europe have agreed to provide pedestrian-protection features in a two-stage commitment that goes into limited effect there in October 2005 and gets considerably stronger in 2010. Automakers have agreed to similar standards that take effect in Japan next year.
Many of the changes being made to conform with the first phase involve passive systems, like redesigned bumper and hoods. But active, high-tech systems seem inevitable, including fiber-optic and radar sensors, exterior cameras and outside air bags that would deploy instantly when an accident occurs - or even before it takes place.
Motor vehicles kill more than 7,000 pedestrians a year in the European Union, about 20 percent of all traffic-related fatalities. In Japan, the 2,700 pedestrians who die annually account for 30 percent of the traffic toll.
But the issue does not have a high profile in the United States, where 5,000 pedestrians die each year, 13 percent of total fatalities. Yet even in the absence of a public outcry, and without pending legislation, pedestrian-safety technology has begun to appear on American-market cars and trucks.
People are rarely "run over," unless they are lying in the road. Instead, they are thrown up and onto the car, where their heads strike the hood or windshield. Since more than half of pedestrian and cyclist fatalities involve head injuries, many new cars, possibly including the 2006 Mercedes-Benz S-Class sedan, will have a softer "deformable" hood. In some cases, the hood will rise at the rear in a crash.
A spokesman for Siemens, the German electronics giant, said the company had developed a bumper-mounted fiber-optic system that can, within 3 milliseconds, or three-thousandths of a second, determine whether the vehicle has just hit a person or an inanimate object like a lamppost. Within 30 to 60 milliseconds, the system can raise the rear of the hood several inches to create what the spokesman, David Ladd, called "a catching device to absorb the impact energy." Since the hood would probably be designed to deform on impact, cushioning a blow, it would be a safer obstruction than unyielding steel.
Mr. Ladd said Siemens had development contracts to explore the technology with two German companies.
A similar "active hood" under development by TRW uses sensors that instruct the hood to rise at the rear, said a spokesman, John Wilkerson. He added, however, that such systems might not be effective with larger, higher sport utility vehicles because "the head impact will be in the very front-end area." S.U.V. systems have focused on passive protection, like reducing sharp edges and softening front ends. Because of concerns about pedestrians, rigid "brush bars"
have largely disappeared from European S.U.V.'s.
The number of S.U.V.'s on American roads presents a challenge. Dr. Samir Fakhry, chief of trauma services at Inova Regional Trauma Center in Falls Church, Va., said people hit by cars were usually thrown onto the hood, but when hit by a large S.U.V., "there's no way they'll get up there."
"Instead," he said, "they'll go up in the air or under the vehicle."
According to a study published in the June issue of the journal Injury Prevention, pedestrians hit by light trucks, a category that includes S.U.V.'s, have a 300 percent higher risk of severe injury than if they were hit by passenger cars. The joint study, by Harborview Injury Prevention and Research Center in Seattle and the Center for Applied Biomechanics at the University of Virginia, analyzed federal data on
Dr. Fakhry said that medical research work on pedestrian safety, especially involving impacts with S.U.V.'s, had lagged behind other automotive safety issues. Inova's pedestrian research is primarily financed by Honda through the federal Crash Injury Research and Engineering Network, known as Ciren.
The National Highway Traffic Safety Administration has conducted research on pedestrian safety, but after some consideration in the early 1990's it decided not to go ahead with requirements for automakers. In the absence of legislation, price and consumer demand are driving the changes.
Autoliv North America is also working on technology in which sensors would act to raise the hood; a spokesman, Patrick Jarboe, said incorporating such a system into a car would be likely to cost $200. "If customers demanded this kind of technology in the U.S., it could become standard within a year," he said.
Honda, a leader in pedestrian safety technology, has quietly incorporated some innovations into most of its current models without charging extra. The Accord, for instance, has windshield wipers that absorb energy when struck, hood hinges that bend on impact and spaces that allow the hood and fenders to deform, cushioning a blow. Andy Boyd, the company's public relations manager, said two million Honda and Acura cars had some or all of these elements.
Honda also developed the world's first pedestrian dummy, called Polar II in its current form. According to Honda's senior safety engineer, Tomiji Sugimoto, the dummy mimics the performance of the human leg, chest and shoulders in a collision with a car. Mr. Sugimoto added that there was considerable research on children's safety inside vehicles, but that little was available on how their bodies fared in pedestrian accidents.
Other carmakers have also introduced new safety designs, though Honda's are perhaps the most far-reaching. The underside of the aluminum hood on the Mazda RX-8 sports car has a deforming egg-crate-style "shock cone" design without rigid ribs, a Mazda spokesman, Jeremy Barnes, said.
Like Honda, DaimlerChrysler conducts extensive pedestrian safety testing, and some features are likely to be incorporated into the 2006 Mercedes-Benz S-Class luxury car, including an active hood-raising system. A Mercedes safety spokesman, Dirk Ockel, said that passive safety measures on new models might include a new hood design with fewer support ribs to stiffen it, a rearranged engine compartment to give more clearance above unyielding engine parts, and modified bumpers and spoilers.
Mr. Ockel said Mercedes saw the greatest potential for reducing pedestrian injury in active safety systems that promote accident avoidance. One such system, he said, automatically applies the brakes when electronic sensors detect that an accident may be imminent. "In many events, the collision can even be fully avoided," he said.
The 2003 S-Class introduced Mercedes's "pre-safe" system that tightened the safety belts and moved reclined seats upright as much as
6 seconds before a crash. In the future, the company says, such systems could be enhanced by radar to provide what Mercedes says are accurate three-dimensional digital models of the road and objects on it.
Mr. Wilkerson of TRW said that pre-crash sensors based on video technology would disploy front-mounted active systems even before impact. These systems, still in the concept stage at TRW, include an "active bumper" whose lower area would move forward to absorb crash energy, and a grille-mounted air bag to catch pedestrians before they are struck by the car itself. Mr. Wilkerson said such video systems would need to be highly accurate, with a wide field of view.
Honda's pedestrian-sensing night vision technology will be an option this year on the Honda Legend luxury sedan in Japan. The infrared system is intended to identify pedestrians from an indistinct blur of dark images, wrap them in an orange frame and display the image through a heads-up display projected on the windshield.
Toyota and General Motors have also developed night-vision systems, though they do not share Honda's focus on pedestrians.
Dr. Fakhry said that any onboard systems, active or passive, would have to work in conjunction with common-sense public safety campaigns.
"Drivers have to be on the lookout for pedestrians," he said.
So what are you folks doing about making cars safer for pedestrians Downunder?