The purpose of the presented study was to analyse the actual situation of children safety in cars with special focus on the misuse topic. In order to completely cover all relevant aspects of misuse both data on the frequency, severity and types of misuse and the underlying knowledge, attitudes and skills of the users were recorded. Thus, a threefold concept of observation and inquiry was constructed. First of all misuse of CRS was observed in public areas such as shopping centres, schools, road side restaurants etc.. The form which was used to classify the misuse configurations was based on the approved form already used in previous studies, but was enhanced further on. Subsequently (by telephone interview) a questionnaire was used to get more information about the misuse-relevant situational context, motives and knowledge of the users.

The field observations were conducted in Greater Berlin and Greater Munich and comprised n=1,076 cases which makes this study the largest sample ever. All relevant driving purposes (shopping, leisure activities, kindergarten, school) and all relevant weather conditions from July 2016 to September 2017 were included in the observations.

In 1,046 cases the children had been secured in CRS, about 30 % thereof in ISOFIX-systems. The misuse rate was 47 %, i.e. the first time ever below 50 %. Misuse rates depend significantly on the type of CRS:​ Higher misuse rates for group 0/0+ and group 1 CRS, typically where installing and securing are two separate actions, and lower misuse rates for group 2/3 CRS. This indicates that especially younger children are in danger not to be secured properly. ISOFIX-systems are significantly better than all other types of CRS. One negative effect compared to the previous studies is that misuse severity is increased. Misuse with heavy or severe impact on the protective capability was most likely to occur to Rearward Facing Systems like car beds and least probably/likely to booster seats and booster cushions, respectively. As far as misuse influencing factors are concerned the results are in analogy to the previous studies:​ Bad weather conditions, change of clothes, short trips < 10 minutes and related driving purposes such as driving to kindergarten and school, short transactions and going home lead to significantly higher misuse rates.

It can be stated that both the majority of the users are convinced of the protective effects of CRS and the sensibility for safety issues is enhanced. Not only parents are target groups, but also the children themselves have their own subjective needs and attitudes towards being secured in CRS, as they are an active part in CRS-use.

Finally recommendations for the improvement of child safety in cars are developed. They are addressed to car and CRS-manufacturers, authorities, traffic safety councils and Research. It is essential to continually learn about frequent misuse of CRS in order to improve the ease-of-use of CRS and communicate it to the relevant target groups.