Background Vision Zero is a long-term goal, decided by the Swedish Parliament in 1997, which means that no one should be killed or seriously injured as a result of accidents in road traffic and the design and function of the road transport system shall be adapted to meet the requirements that follow from Vision Zero. Based on this decision and strategy several different interventions have been implemented to create a road environment which allows human mistakes. In Sweden state is responsible for roads in rural area and municipalities for roads in urban area. The aim of the study is to evaluate the effects of road safety measures for the group severely injured (ISS > 8) in the county of Västmanland during years 2003–2014 in state and municipal road network.

Methods A longitudinal registry study of a statistical cohort comprised of the county of Västmanland. The study is based on data from emergency hospitals. These data have been combined with data from a national base for road data, NVDB. Descriptive statistics together with trend analysis are applied.

Results Preliminary results for 626 severely injured – 372 injured in municipal roads and 254 in state roads – means that 60% have been injured on municipal road network. Cyclist and pedestrians dominates the group by 83%. Of cyclists are 72 % 45 years and older, while 88% of pedestrians are 45 years or more. On state roads 70% of road users are motorists and they are younger than road users in municipal roads. On the municipal road network 69% were injured in single accidents, while the corresponding proportion of the state road network is 51%.

Conclusions The group severely injured in municipal roads is dominated by unprotected road users mostly older than 45 years, while protected road users are injured in state roads and are younger than injure in municipal roads. These results will be useful for future road safety measures for severely injured.