Is 30 km/h a ‘safe’ speed? Injury severity of pedestrians struck by a vehicle and the relation to travel speed and age

• We study relation between mean travel speed and injury outcome for hit pedestrians.
• Both mean travel speed and age have considerable influence on the injury outcome.
• 30 km/h might not be sufficiently low speed to prevent severe injuries.
• Fatal accidents are rare at locations with mean travel speeds below 40 km/h.
• 75 years and older are highly overrepresented in the fatal accidents.

This study uses Swedish accident data for the years 2004–2008 to analyze the relationship between injury severity for pedestrians struck by a vehicle and the speed environment at accident locations. It also makes use of a multinomial logit model and other statistical methods. Speed measurements have been performed at accident sites, and the results show that there was a relationship between the (1) mean travel speed and (2) the age of the pedestrian struck and the injury severity and risk of fatality. The data also shows that even though fatal accidents (excluding run-over accidents) are rare in speed environments where the mean travel speed is below 40 km/h and severe injuries are rare below 25 km/h, over 30% of severe injury accidents occur in speed environments below 35 km/h. This indicates that 30 km/h speed limits might not be as safe as previously believed. The current speed policy needs to address this issue. To the author's best knowledge this is the first study that analyzes the relation between mean travel speed and injury severity for pedestrians struck by vehicles.