Techsplanations: Pedestrian Safety Design

For decades, engineers have worked diligently to make people safer inside their vehicles. But more recently, safety engineers and designers have begun to make people safer outside of vehicles in the event of a collision.

Pedestrian safety design hopes to curb the more than 4,000 people killed every year in the United States. While there are no requirements for pedestrian safety in America, Europe has a growing number of rules and regulations carmakers must meet. Since many vehicles are sold in both the U.S. and Europe, those safety features arrive in America.

Unlike other safety engineering that is typically not seen, pedestrian safety design directly impacts the exterior styling of a vehicle and can sometimes work against other safety features.

For example, many cars now come with lower front ends, which may make them look faster, but also helps if a pedestrian is hit. If struck, a pedestrian is pushed up onto the car instead of smashed into it. (Pickups and SUVs often do poorly in pedestrian safety testing because of their bigger bumpers and higher front ends cause more impact on a pedestrian.)

Since a pedestrian struck by a vehicle is lifted up onto the hood, designers and engineers have created ways to lesson a person's impact on the hood. In particular, they've looked at ways to cushion a blow to the head upon impact with the car.

Designers have engineered more space between the hood and the engine, allowing more give in case of a collision. From a design perspective, the higher hood, especially closer toward the windshield, gives vehicles a distinctive look. About 10 years ago, Volvo created a 3-inch gap between the hood and the top of the engine. (Another feature that is worked into pedestrian safety is an engine's plastic cover, which also gives in a pedestrian accident.)

Other less noticeable design elements include the removal of hood ornaments, which could snag or cut pedestrians; side mirrors that fold in toward the door, and even door handles that are more flush with the car's sheet metal.

Another challenge is creating exterior items that can break away when a pedestrian hits them but still function correctly. For instance, windshield wipers are often tucked down under the higher hood, but still created to break off if a pedestrian hits them.

Other changes to help pedestrians work against the vehicle in other accidents. Engineers have designed bumpers that are softer on impact for pedestrians. But initially, that did not help cars in other crashes, so designers had to find an acceptable medium.

Obviously, it's a difficult task to create a 4,000-pound vehicle that doesn't injure or kill a person if it hits him or her at speed. But using things like advanced crash test dummies and finding ways to mitigate the damage a vehicle can do to a person is a good start.