During WWII, the national speed limit was reduced to 35 mph to save gasoline and tire wear. A trip across Utah could take nine hours instead of five.
Bicycles have no speed limits in the UK, but you can get charged with ‘cycling furiously’.
A 1992 study of 100 different sites in 22 states showed that when the speed limit was raised the number of accidents decreased by 6.7%. When the speed limits were lowered the number of accidents increased by 5.4%.