The International Transport Forum has issued a report "confirming existing scientific evidence" that speed has an influence on road fatalities.
The study examined how the road safety performance in ten countries changed after they changed speed limits or introduced automatic speed cameras on a large scale.
The cases found that an increase in speed was accompanied by a higher number of crashes and casualties. A decrease was associated with fewer crashes and casualties.
In no case did an increase in mean speed coincide with fewer crashes or casualties.
The report states that: “These results confirm the existing scientific evidence that speed has a direct influence on the occurrence of traffic crashes and on their severity.
“According to a widely used scientific formula, every 1% increase in average speed results in a 2% increase in all injury crashes, a 3% rise in fatal and severe crashes and 4% more fatal crashes. “
The report recommends to:
- Reduce the speed on roads as well as speed differences between vehicles.
- Set speed limits based on the safe system principles, i.e. at a level that humans can survive without dramatic consequences in case of a crash.
- Introduce compensation measures where speed limits are increased; for instance, stricter enforcement or a safety upgrade of the road infrastructure.
- Use automatic speed control to effectively reduce speed.
Working towards a safe system, the authors propose the following as reasonable speed limits:
- 30 km in built-up and residential urban areas where motorised vehicles and vulnerable road users share the same space;
- 50 km in other urban areas with intersections and high risk of side collisions;
- 70 km on rural roads without a median barrier and a risk of head-on collisions.