Pedestrians account for almost 2/3s of the 1.2 million individuals that are killed yearly in a traffic related incident. Obviously, pedestrian safety is a major concern and recently engineers have started to design cars that have pedestrian protection systems installed in order to reduce the risk of a pedestrian being injured by a vehicle should they be struck.
The pedestrian protection systems include a redesigned hood and bumper as well as the pillar and windshield. These systems are being designed to be softer and more energy absorbing without the structural integrity being affected.
Pedestrian Crashes
Many pedestrian crashes will involve a pedestrian being hit by a forward moving vehicle. The pedestrian is typically hit with two impacts, the first from the vehicle and the second from the ground. The car is what typically causes the most damage.
When designing pedestrian protection systems, engineers studied the interaction between the car and the pedestrian. In these crashes a pedestrian is first hit in the lower limbs by the bumper of the car, then the front part of the hood of the car connects with the individual's pelvis and upper thigh, the head of the pedestrian then strikes either the top part of the hood of the car or the windshield.
Design of Pedestrian Protection Systems
The majority of pedestrian deaths happen because of a traumatic head injury. Other injuries that frequently occur include lower limb injuries such as the long limbs and the knees. While these injuries are typically not fatal, they do lead to permanent disabilities. To protect both cyclists and walkers, cars are installed with a frontal protection system. This is a device that is fitted to the front of a car. The design of a vehicle has been shown to have a big impact on the severity and scope of the injuries that occur to a pedestrian involved.
To protect the head of a pedestrian, a gap of around 10 centimeters is needed between the engine and the hood in order to allow enough room for the sheet metal of the hood to give, reducing the risk of serious head traumas. However, designing vehicles with this type of space can be difficult due to design restraints involving style and aerodynamics. There have been a couple of car designs that have a pop-up hood that initiates via sensor if an impact is felt.
To help protect the limbs of pedestrians, engineers have made the bumpers of vehicles softer. This is the place where most limb injuries occur, so by making the bumper have more give, the bend of the knee is limited and reduces the risk of these types of injuries from happening.
Overall, the risk of serious injury if struck by a car while walking or riding a bike is significant. However, with new designs in the front ends of the car, including the bumpers and hood have helped decrease the severity of the injuries that occur. With further technology and design a reduction in the number of fatal injuries of pedestrians should decrease over time.
