Recent accident studies [3] show and confirm that occupant severity in frontal car to car accident depends on vehicle mass and size.

Despite the introduction of the Frontal Impact regulation ECE R94, the aggressivity rates of heavy vehicles in front to front accidents are mostly unchanged or worse in some countries. A difference between cars which comply with R94 compared to all ages of cars has been observed. This phenomenon has a direct influence on injury rates of light cars compared to heavy ones.

However, this situation is not a ’fait accompli’ and can be solved by changing front end force and compartment strength difference amongst cars mainly responsible for this situation. This paper evaluates and explains why the current frontal impact test using deformable element did not solve this problem and shows its impact on accident data.

It proposes also some different approaches of possible improvements in test protocol and car design for solving this main passive safety issue. Slight modifications will allow light cars to reach the same level of protection as heavy cars in frontal impact accident.

Possible reductions in severe injuries and fatalities are forecast based on the slight modifications to the test protocol. This will allow rates of serious injury and fatalities in light cars to more closely match those in heavy cars.

The influence of vehicle mass on injury severity rate cannot be completely eliminated. However, the effects could be reduced. The same severity rate for vehicles of different mass and size will remain an unreachable goal. However, reducing and harmonizing impact severity rates among vehicles in a regulatory test is one of the first priorities to reduce the number of accident victims.