Too many people get hurt and killed in automobile accidents. What we need is a way to soften the impact and what I propose here has probably already been manufactured and found wanting but I’ve never seen it so I think it needs to be written up, built and tested.
Cars could be built with an automatically extensible bumper. This bumper could be designed with a ranging sensor to determine when something was approaching too rapidly, which would cause the bumper to go shooting out about a meter, contacting the oncoming object before the solid place where it would have hit the car on the normal rigid bumper. The tubes used for propelling the bumper out would be designed in such a way so as to absorb the impact inertia of the car, such as a dashpot.
The image is from Answers.com. The bumper could be tuned to the standard impact speed of up to 30 mph so that when the full extension was achieved before impact and the full amount of extension was collapsed after impact the car would come to rest without any injury to the car or its belted passengers. It could have an approach speed detector and adjust the after impact deceleration rate to achieve a minimum stress on the car and the occupants. A dashpot differs slightly from the above diagram in that there is a built in leak between F and E or the outside so the compressed gas does not bounce the piston back up. For the use of an impact softener there could be a high pressure valve which would permit some gas to be shot into the blue region to push the cylinder out before an impact occurred.
This concept could be tested without building the approach sensors or the explosive extension tubes by simply attaching a collapsible concentric-tube telescope bumper under a crash test car’s body. This simulating test device could be tested at increasingly high approach speeds into a testing barrier until the ideal configuration was achieved.
Helicopters already have long extension landing gear to soften hard landings so there is some experience already to be had for this inertia absorbing concept. With helicopters this same type of equipment could be built in so that when a copter was descending too fast the landing gear could be hyperextended and absorb more shock. At present they merely have a long stroke landing gear but I am proposing having it extend another meter or more during a crash sequence.