Trying to reduce mortality and morbidity attributable to road traffic accident is a public health issue. Many risk factors such as: speed, drowsiness, drugs and alcohol consumption, state of the car, have been identified and have permitted the development of prevention policies. in contrast psychological factors remain poorly studied, particularly emotional state. However it is well known that emotional reactivity have an impact on behavior. One of the main objectives of this study is to assess in what extent the emotional reactivity, whether it is hypo or hyper reactivity, is a factor involved in road-accident responsibility. 955 participants were identified within 72 hours after a car accident. An assessment of drivers’ responsibility for the accident was conducted along with a survey of their activities and emotional reactivity immediately prior to the accident (valence, arousal). The results revealed that emotional reactivity is significantly associated to the drivers’ responsibility, suggesting that emotional hypo or hyperactivity is a significant source of accidents. This study discusses various approaches for a better understanding of the link between accident and emotional state. Moreover these results permit to suggest some possible preventive interventions.