[1] Karolinska Inst, Dept Publ Hlth Sci, Stockholm, Sweden
[2] Swedish Transport Adm Trafikverket, Traff Safety Unit, S-78189 Borlange, Sweden
[3] Malardalen Univ, Sch Hlth Care & Social Welf, Vasteras, Sweden
[4] Uppsala Univ, Inst Housing & Urban Res, Gavle, Sweden