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New study calls for speed limit reductions

New study calls for speed limit reductions

A new report by the International Transport Forum for the Organisation for Economic Co-operation and Development (OECD) suggests that lower speeds make roads safer.  

The study examined how the road safety performance in 10 countries changed after they changed speed limits or introduced automatic speed cameras on a large scale.  

All the cases indicated a strong relationship between speed and the number of crashes: An increase in mean 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.  

These results, said the OECD, confirmed the existing scientific evidence that speed had 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.   

Thus, reducing speed by a few km/h could greatly reduce the risks of and severity of crashes, it is claimed.  

The report recommended:  
  • Reduce the speed on roads as well as speed differences between vehicles          
  • Set speed limits based on the ‘Safe System’ principles - at a level that humans could survive without dramatic consequences in case of a crash  
  • Introduce compensation measures where speed limits were 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 as reasonable speed limits: ·        

  • 30 km/h (20 mph) in built-up and residential urban areas where motorised vehicles and vulnerable road users share the same space           
  • 50 km/h (30 mph) in other urban areas with intersections and high risk of side collisions          
  • 70 km/h (43 mph) on rural roads without a median barrier and a risk of head-on collisions.   

The report notes that lower driving speeds generally improved peoples’ quality of life, especially in urban areas. They also reduced emissions, fuel consumption and noise.  

The report can be viewed at: https://www.itf-oecd.org/sites/default/files/docs/speed-crash-risk.pdf