Leg protection and air bags
Leg protection in the form of crash bars may only prevent injuries from direct contact in collisions of the side of the PTW with a car/object. Other forms of leg protection have been studied to prevent injuries in frontal collisions by absorbing energy and directing the trajectory of the legs. Unfortunately, these devices may change the directory of the rider in such a way that the upper parts of the body are more likely to be injured.
Experiments with air bags show that the speed of the PTW rider who departs from the PTW during a frontal collision can be considerably reduced. Such devices are tested in full scale collision tests in which a moving PTW with a dummy rider collides with a moving or stationary car. The accelerations and loads on parts of the dummy are recorded and translated into injury patterns. The resulting injuries will depend on the speed of the PTW, the type of PTW, the seating position of the rider, the angle and point of collision with the of car and the type of car. Only a limited number of these variables have been included in such tests. For this reason it is difficult to decide how effective devices such as airbags or leg protectors are in practice. It seems that a combination of such devices will be needed to prevent injuries in a number of types of collision and to avoid that devices are beneficial in one type of collision but have adverse effects in others, or are effective in preventing one type of injury but introduce others. These devices are not likely to have much effect on loss of control accidents.
Most tests have been done with a motorcycle at a speed of about 60 km/h. It would be interesting to know the results of tests with scooter or step through types of moped.
The experiments with air bags are based on the idea that reducing the speed and controlling the trajectory of the PTW rider during a collision is preferable to fixing the rider to the PTW. A departure from this idea is made in the design of one particular type of PTW . In this case the PTW is designed as a safety cell which largely protects the rider from direct contact with collision objects among other things by means of a roof frame and seat belts. Tests showed positive effects with several types of collision.