Bringing the pedals to the feet

Engineers look at helping short drivers get some distance from air bags

By Anita Lienert / The Detroit News
Tuesday, March 7, 2000

Any woman who’s been pregnant or shops in the petite department knows that a vehicle with adjustable pedals makes a lot of sense.

A Delphi Automotive Systems study on the effectiveness of adjustable pedals use confirmed those common-sense suspicions. And engineers have ideas for improving future designs.

“Our tall occupants did not like this product,” said Chantal S. Parenteau, a Delphi biomechanical engineer. “But women and short-statured occupants felt more comfortable moving away from the air bag.”

Safety is a critical factor in getting those shorter than 5 feet, 2 inches away from the air bag. An air bag typically deploys at about 200 mph; studies have shown shorter drivers who can’t reach the pedals sometimes as close as eight inches or less to the steering wheel.

Most experts recommend drivers position themselves at least 10 inches from the steering wheel.

The Delphi study said adjustable pedals increased the chest-to-steering-wheel distance, especially in larger vehicles. The power pedals also increased the abdomen-to-steering-wheel distance, a critical factor for pregnant women.

Another benefit was that adjustable pedals tended to reduce foot and ankle injuries be reducing heel lifting movements.

Automakers say that adjustable pedal use is likely to grow. Teleflex Automotive Group, a major producer of adjustable pedal system, said its production has increased from 30,000 units in 1998 to more than 2 million this year.

Still there are some disadvantages to adjustable pedals, Parenteau said. Test participants, including a woman nine-months pregnant, said they felt limited by several factors. As they moved their seat rearward, their visibility became obstructed by the rim of the steering wheel.

Also, they had to stretch their arms more to reach the steering wheel. In addition, there were complaints about knees hitting the steering wheel.

Possible engineering solutions? “We need to consider increasing the seat height and offering an adjustable steering wheel with the adjustable pedals,” Parenteau said.