This report presents results of literature reviews of the effects of vehicles crashworthiness, weight, and compatibility on crash severity, as well as effects of electric vehicles on crashes and crash severity.
Empirical studies have investigated the relationship between crash test results (in programs such as Euro NCAP) and injury severity in crashes, changes of vehicles crashworthiness over time and differences between different types of vehicles.
None of the studies indicates that the improvement of crashworthiness over time has started to slow down. Although there are limits for the survivability of serious crashes, studies of racing cars show that it is theoretically possible to construct cars in which even crashes at very high speeds can be survived.
Heavier vehicles provide better protection for their occupants than lighter vehicles. For light vehicles, empirical studies show that increasing weight by 100 kg reduces fatality risk by 7.5% on average in collisions with other light vehicles.
The relationship between weight and injury risk is stronger for more serious injuries than for slighter injuries, and has decreased over time. The latter is probably due to general improvements of vehicles’ crashworthiness, as well as improved compatibility.
Weight differences between the own vehicle’s and crash partner’s weight affect injury severity as well. The larger the difference in weight, the larger is also the difference in injury severity.
However, in heavier vehicles, the weight of a collision partner affects own injury risk less than in lighter vehicles. Injury risk among collision partners has been found to increase with the own vehicle’s weight. Increasing the own vehicle’s weight by 100 kg increases fatality risk among collision partners by 6.6% on average.
Crashworthiness is the degree to which vehicles protect occupants from (severe) injuries in crashes. However, vehicles crashworthiness can also affect injuries among crash partners.