Very often pedestrians are hit by cars. For instance, in the USA about 64,000 pedestrians are injured in motor vehicle collisions each year.
But there is good news: such accidents are declining partially because vehicle designs have been changed in order to reduce injuries in the event of car - pedestrian collision.

Flying Bodies

Engineers and researches spend a lot of time investigating real-world crash data, using computer simulations of crashes and carrying out actual crash testing with full dummies and test devices (so called impactors), representing portions of dummies’ out bodies (such as a leg or a head).
According to the results of researches, most of pedestrians are hit by the front part of the vehicle but the consequences vary widely depending on many factors, including the type of vehicle, its speed and the height of the pedestrian. For example, when a vehicle hits a pedestrian, crossing the street, the person is usually struck by the vehicle’s bumper and the front edge of the hood. A taller vehicle, such as an SUV, injures higher parts of the body. At the same time the increased vehicle’s speed means the pedestrian will likely be propelled up over the hood. But it’s not even as “simple” as that.

Changes in Vehicle Design

To solve the problem the automakers began focusing on cars’ features which can cause the harm. For example, protruding hood ornaments were embedded in the grille. They also may be designed in such a way to collapse on impact. With the same aim the exterior mirrors are now mounted on springs. Even a styling feature like recessed door handles help to reduce pedestrian injury.

In recent years, vehicle design has focused on making subtle changes to the front end of the vehicle that aren’t very vivid to consumers. One example is changing the way of attaching the fenders, hood and windshield wipers, in order to preserve their strength but at the same time give them ability to collapse when hit by a pedestrian. This type of features is characteristic for vehicles from Acura, Honda, Infiniti, Lexus, Nissan, Toyota, Volkswagen and Volvo among others have these types of features.

Hood design and engine compartments also have got little changes recently. Nowadays many vehicles sold in the USA are equipped with braces supporting the hood that crush when they are impacted from above, for example by a person’s head. In addition, the automakers provided a plastic engine cover which also serves to soften the impact. The same is achieved by increasing space between the hood and the cover. Beginning in 2001, Volvo, for example, provided 3 inches of deformable space between the hood and engine in order to protect pedestrians with its new vehicles. As a result, when the company had to decide which engine to choose between two V8 engines for its XC90, one engine was rejected because of the fact that it protruded into the company’s 3 inches of necessary safe space.

However the engineers in the US still have another key problem – the front bumper. The opposite situation takes place with the vehicles in Europe and Asia. In these regions there are many more collisions, consequently there are more governmental standards which regulate them. That’s why bumpers are provided with larger crush space, different supports for the plastic bumper cover to reduce leg injury. Unfortunately, these “softer” bumpers are not very suitable for the 5-mph bumper test to assess repair costs. That’s why these types of bumpers are not generally used on vehicles in the U.S.

Another problem with bumper design for U.S. vehicles is connected with the front airbag sensors that are located in the bumper. It is very difficult to address pedestrian safety and still have the sensors effectively trigger the front airbags, especially in low-speed collisions. To solve this problem the engineers sometimes add high-density foam behind the plastic bumper cover – this is a method used on all Toyotas.
What is in the Future?

Automotive engineers and researchers, as well as experts from the safety and medical fields, continue to study vehicle-pedestrian collisions, in order to develop other ways to reduce pedestrian injury. Their main task at the same time to maintain a high level of safety for the vehicle’s occupants. Honda continues to be a leader in this research area with the development of its POLAR-II dummy. This is the only dummy which currently exists that can measure pedestrian impact. The company uses the dummy to carry out computer modeling of pedestrian impacts and lends it to other automakers and industry groups for testing.

Another popular safe design feature is a pop-up hood system. It is designed in such a way to lift the hood a few inches in the area closest to the windshield, and to give a larger cushion of space underneath it in the event of a pedestrian impact. This feature is currently in use on some Hondas in Europe. Nissan intends to debut it on its Skyline coupe when it goes on sale in Japan this autumn. However at the present time none company is going to provide this safe system in vehicles in the USA.

Roger Levinsen

Technorati tags: Car Accidents, Car Crash, Pedestrian’s Safety