Accident or suicide? Improvement in the classification of suicides among road traffic fatalities in Sweden by extended psychosocial investigations, during the years 2010–2019

•Suicides are difficult to distinguish from accidents among road traffic fatalities.•Psychosocial investigations helped to identify more suicides.•Psychosocial investigations helped to resolve many “undetermined” causes of death.•The improved classification will help prevention of suicide deaths in road traffic.