Search Results

In the design of a safe road transport system there is a need to better understand the safety challenges lying ahead. One way of doing that is to evaluate safety technology with retrospective analysis of crashes. However, by using retrospective data there is the risk of adapting safety innovations to scenarios irrelevant in the future. Also, challenges arise as safety interventions do not act alone but are rather interacting components in a complex road transport system. The objective of this study was therefore to facilitate the prioritizing of road safety measures by developing and applying a new method to consider possible impact of future vehicle safety technology. The key point was to project the chain of events leading to a crash today into the crashes for a given time in the future. Assumptions on implementation on safety technologies were made and these assumptions were applied on the crashes of today.

The European crash test program, Euro NCAP, has since its launch presented results of some 80 individual car models. The improvements in the general level of protection have been substantial. While the intention of the test program is to stimulate the use of best practice, and not to predict real-life outcome, it is nevertheless important to validate the positive development, and to pinpoint potential areas not included in the laboratory safety ratings. In this study, Euro NCAP rating results were compared with a comprehensive car model safety rating method based on real-life crashes, developed by Folksam. In addition, correlation with relative injury risks was also studied. In the Folksam method, the ratings are based on the risk of fatalities and long-term consequences due to injury. The car models were grouped together according to the Euro NCAP star ratings.

This paper presented a part of results from an ongoing project for pedestrian protection, which is carried out at Chalmers University of Technology in Sweden. A validated pedestrian mathematical model was used in this study to simulate vehicle-pedestrian impacts. A large number of simulations have been carried out with various parameters. The injury-related parameters concerning head, chest, pelvis and lower extremities were calculated to evaluate the effect of impact speed and vehicle front structure on the risk of pedestrian injuries. The effect of following vehicle parameters was studied: stiffness of bumper, hood edge, hood top, windscreen frame, and shape of vehicle front structures. A parameter study was conducted by modelling vehicle-pedestrian impacts with various sizes of cars, mini vans, and light trucks. This choice represents the trends of new vehicle fleet and their frequency of involvement in real world accidents.

The safety situation in Sweden has improved the last decade but the positive trend has levelled out the last few years. The parliament has taken interest in the problem and has formulated the “Vision Zero” as a new strategy. The Vision Zero claims that it is not acceptable to have fatalities and injuries leading to long-term problem in the road transport system. The government has further focussed the work by a special 11-point program for traffic safety and an investigation how to establish legislation giving all system designers larger responsibility for the safety level in the road transport system. New better knowledge is needed to support the new strategy. Changing the focus from accidents to preventing severe injuries will help to solve the problem. More co-operations between the various traffic safety disciplines are urged for in the design of a crashworthy road transport system, where vehicles, infrastructure, speed and human failures are handled simultaneously.

Injury rating is an important issue in the field of traffic safety. The injury pattern can be obtained either from the scene of the accident, including all severity grades, or from the frequency of those fatally injured. Less attention has been paid to the long-term consequences of an injury. Furthermore, the existing rating system is based on the medical status at the scene of the accident or immediately after and judges only the risk of death. Nygren showed that for many body regions the AIS values did not reflect the outcome of a trauma expressed in permanent medical disability. In this study, 339,675 accidents with private cars were analyzed with respect to injuries to car occupants. In these accidents, 14,361 persons were injured. The risk of permanent disability due to different injuries is derived and linked to AIS values to different body regions. A rating system for injuries based on the risk of death or permanent disability is proposed.