29-08-2013, 01:04 PM
BUMPERS DO LITTLE TO PROTECT CARS FROM DAMAGE
BUMPERS DO LITTLE .pdf (Size: 10.11 KB / Downloads: 22)
INTRODUCTION
Bumpers on most midsize cars do a poor job of protecting the vehicles in low-
speed collisions. according to recent tests, and the cost of repairs following
minor fender-benders can be surprisingly steep.
For consumers, the latest test scores by the Insurance Institute for Highway
Safety, a research group funded by the insurance industry, may be more
meaningful than those derived from high-speed crash tests that simulate
traffic accidents that are more likely to be deadly. The bumper tests are
designed to mimic collisions that are more common in parking lots and slow
commuter traffic. Many drivers have been involved in such accidents or have
come close. The increasing repair costs have resulted in higher insurance
claims, which have in part driven the research group to study the trend
closely.
Evolution of the car bumper in the past 35 years has meant that formerly one-
piece bumpers are now integrated into the vehicle’s front-end design. This
happened in part because the new rules don’t require bumpers to be as
strong and protective. That means consumers wind up paying thousands of
dollars to fix damage from even a minor collision, The total repair cost for
damage from four impact tests – on each car’s front and rear bumpers and
front and rear corners – ranged from $4,277 for the Mitsubishi Motors Corp.
Galant to $9,052 for the Nissan Motor Co. Maxima.
The damage costs show how bumper design has slipped over time as
manufacturers focused more on protecting passengers in high-speed
crashes. Easing standards has allowed auto manufacturers more flexibility in
designing vehicles foe aesthetic appeal. For comparison, the IIHS tested a
1981 Ford Motor Co. Escort. The Escort, which was built during the height of
strict federal regulations, has large wide bumpers and sustained no damage
in the corner tests. After the four tests its damage totaled $469. The car’s
bumpers contribute to its overall clunky styling and its performance in high-
speed crashes would probably be unacceptable by modern standards.
The National Highway Traffic Safety Administration issued its first regulation
for the bumpers of passenger cars in 1971. The rule said a vehicle’s bumpers
had to protect “safety-related components” such as headlamps and fuel
systems in a series of crash tests at five miles per hour on the front bumper
and 2.5 mph in the rear. Federal requirements got more stringent over time,
allowing less damage and boosting rear-impact test speed to five mph to
more closely match the frontal standard. Bumpers also had to withstand
three-mph corner impacts. However by 1983 a rule change lowered impact
speeds to 2.5 mph for front & rear and 1.5 mph for corners.
In the tests, each car collides with a steel barrier that is shaped like the front
end of a car and is built with a wide plastic cushion and a flexible cover similar
to the energy-absorbing bumpers and bumper covers on most cars. The
institute has redesigned its crash barriers to look and respond more like the
bumper of another car instead of a flat wall. The full test includes four
impacts: front and rear full-width crashes at six miles an hour and front-and
rear-corner bumps at three miles an hour.