Speed kills: new global study confirms strong link between crash risk and vehicle speed
A new, large scale, international report confirms what safety experts around the globe have long known: that speed has a direct influence on the occurrence and severity of traffic crashes, and that lower speeds make roads safer and result in fewer deaths.
Inappropriate speed is responsible for 20 to 30 % of all fatal road crashes, according to "Speed and Crash Risk," which examined how the road safety performance in ten countries improved after they changed speed limits or introduced automatic speed cameras on a large scale.
The report, released on Thursday by the Paris-based International Transport Forum, an intergovernmental organization with 59 member countries within the Organization for Economic Cooperation and Development (OECD), analyzed cases from: Australia, Austria, Denmark, France, Hungary, Israel, Italy, Norway, Sweden and the United States.
The researchers' goal was to establish a link between vehicle speed and crash risk by documenting the recent changes in speed limits or the wide-scale implementation of automated speed enforcement and whether those measures delivered the safety impacts that theoretical models suggested.
The results were clear: "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," the report said. "A decrease was associated with fewer crashes and casualties. In no case did an increase in mean speed coincide with fewer crashes or casualties."
In France, for example, during a several year period after speed cameras were introduced in 2003 following a decision by then President Chirac to make road safety a national priority, the mean speeds fell by 8.9 km/h (about 5.5 miles per hour) on secondary roads and by 7.7 km/h (just under 5 miles per hour) on two or three lane highways. And fatalities decreased by 25-35 % in rural areas, 38% on urban motorways and 14% on urban roads.
The report, which stressed that reducing speed slightly can greatly reduce the risks and severity of crashes, made the following recommendations:
— introduce compensation measures where speed limits are increased, like stricter enforcement or a safety upgrade of the road infrastructure;
— reduce the speed on roads as well as speed differences between vehicles;
— use automatic speed control to reduce speed;
— implement the following speed guidelines: 30 km/h (about 18-19 miles per hour) in built-up and residential urban areas where vehicles and people share the same space; 50 km/h (about 31 miles per hour) in urban areas with intersections and high risk of side collisions; 70 km/h (about 43 miles per hour) on rural roads without a median barrier and risk of head-on collisions.
In addition to saving lives, the report noted that lower speed limits have other societal benefits: they improve citizens' quality of life, especially in urban areas, and reduce emissions, fuel consumption and noise.