Abstract
Keywords: individual safety, occupant sensing, seat belt reminder, child seat tagging, reversible safety systems
Europe enjoys constantly decreasing numbers of traffic fatalities per year. While in the EU25 there were 50.396 fatalities in 2001, the number was reduced to about 39.200 by 2006. In North America however, the number of fatalities remains on a constant level (2001: 42.196; 2006: 42.642). In the past, passive safety focussed mostly on improving occupant safety in frontal and lateral crashes. But whiplash injuries are now receiving more attention, as e.g. in the UK, 80% of all personal injury costs are attributed whiplash claims.
One can ask if further developments of passive safety systems are still needed or if it is smarter to invest in crash avoidance systems. There is no single answer to this question but it is clear that a continuous improvement of passive safety systems has a high potential for decreasing the number of traffic fatalities worldwide.
The goal of passive safety systems is to reduce the injury risk in case of a crash, but lack of risk awareness or just carelessness among drivers and passengers often leaves two key safety elements ineffective: the seat belts and the headrest. Advanced seat belt reminder systems motivate 80% of unbelted vehicle occupants to use this most effective restraint system. Equipping all seating positions of vehicles with seat belt reminder systems would reduce significantly the number of traffic fatalities simply by increasing the buckle up discipline. Improved design of headrests can contribute to the reduction of whiplash injuries. But as approximately 75% of the headrests are adjusted to the wrong height, headrest design alone will not solve the issue. Smarter solutions like automatic height adjustment tailored to the occupant size should be taken into consideration.
In general any restraint system component individually tailored to the occupant could offer optimised protection. Current restraint systems are mainly optimised for the 50%-male, not offering optimal protection for smaller or larger occupants. "Individually tailored" has to be translated as detecting and monitoring the type, size, age, position and health condition of the occupants and to adapt the restraint systems accordingly. Pre-crash sensing would help to perfectly time the individual restraint systems deployment. The industry has to re-design the concept of passive safety in cars. Individualizing the passive safety opens the possibility to sell to the end customer a "safety sensation" and motivate him to invest in passive safety.
Some car manufactures have introduced a combination of passive and active safety systems. A smart sensor fusion leads to an economic and robust next generation passive safety system. An important first step is made by using pre-crash sensing to pre-set the passive safety system. In a next step a "T0 sensor" in the front end should verify the pre-set and activate the restraint systems. As the timeframe for the restraint systems activation can be increased, a new generation of reversible and non-pyrotechnical systems can be taken into consideration. Sensing systems inside of the car will deliver the relevant occupant information.
Next generation adaptive reversible low cost passive restraint systems and active crash avoidance systems have the potential to lower the number of traffic fatalities.