What Accident Analysis Tells About Safety Evaluations of Passenger Vehicles - Contributions ofPrimary and Secondary Safety to Overall Safety and Consequences for Safety Ratings

In the past, the overall safety of passenger vehicles was dominated by secondary safety features, the ability of vehicles to reduce the consequences of accidents by mitigating injuries. In the last ten years, crash avoidance devices which can reduce the likelihood of accidents were introduced into cars. These devices support the braking of drivers, such as brake assists, or they reduce the likelihood of skidding, such as ESC, others will follow. Accident research clearly and increasingly shows the effectiveness of such devices under European road conditions. Although road conditions in the U.S. are different, there are positive indications as well. In Europe, for belted occupants, ESC-effectiveness is estimated to be higher than airbag effectiveness. The accident data, indicating this, has been consistent for a couple of years. This paper provides accident data predicting the amount of safety benefit to be attributed to the different safety features in terms of risk reduction. This might help to overcome the problem that current 4 and 5 star cars are said to be in fact better than cars with fewer stars, while there is no significant difference between 4 and 5 star cars in real world accidents. It is the goal of the paper to quantify the degree of the total safety, reflected by a crash test based rating, like the current rating in Europe.