Introduction of speed limit 30 km/h in large zones and entire cities to achieve the goal of sustainable urban development: Processes, discussions, implementation and effects

We have collected, analysed and presented experiences from European cities that have introduced a speed limit of 30 km/h in large zones or entire cities to achieve the goal of more sustainable urban development. The purpose was to lay the foundation for more knowledge-based discussions related to the use of a speed limit of 30 km/h in large zones, entire cities or as a general speed limit in densely populated areas in Norway. We found that the measure contributed to a reduction in speeds and significant reductions in the number of traffic accidents in all the cities for which we found results, as well as to a number of other factors that contribute to more sustainable urban development. The inhabitants were positive before the implementation and even more positive after. The cities normally initiate the speed limit reductions. Whether the measure is implemented depends mainly on whether the superior authorities can and will prevent the cities from doing so.