The number of road accidents that lead to death or serious injury is surprisingly high, often due to driver error, at some 24,000 a year. There will be less in 2020 due to reduced traffic flows but they are likely to return to pre-pandemic levels as the economy recovers.
It is easy to check road safety records on the government supported crashmap website. The information goes back over some twenty years and includes locations, date and short descriptions of each accident. Fuller police reports are also available.
The frequent cause of accidents through driver error can be appreciated when we examine what a driver actually sees and understands. There is a limit to the amount of information we can digest in a short time span as well as severe limitations on the speed the brain interprets what our eyes think they see.
Therefore the faster drivers travel the shorter the time they have to understand what is happening, especially if it is unexpected, and react safely. There is a disproportionate relationship between vehicle speed and the likelihood and severity of accidents. A pedestrian who is hit by a vehicle travelling at 40mph has an 80% risk of suffering a fatal or serious injury. If the vehicle is travelling at 20mph the risk is not 40%. It is 5%.
Apart from statutory speed limits, or in conjunction with them, vehicular speed can be reduced by traffic calming. That is by changing the nature of the road so that drivers feel that they should slow. These changes to a road can be carried out in ways described in the traffic calming regulations and explained in the traffic calming government guidance note. The regulations allow very wide interpretations and the use of landscape design as well as little or no traffic signs within a 20mph zone.