Speed and crashes
Speed is a factor in about a third of all fatal road crashes. Not only does the risk of a crash increase with speed, so does the risk of severe injury.
The survival chance decreases drastically at high collision speeds with motorized vehicles, particularly for pedestrians and cyclists. The precise relation between speed and crash risk depends, among other things, on the complexity of the traffic situation.
Not only the absolute speed, but also the speed differences determine the crash risk. Therefore, speed limits can make a large contribution to road safety, particularly on regional and local roads.
For more details:
Fact sheet The relation between speed and crashes (pdf)