If the speed limit is 65 but in practice driving 70 is still safe enough, we should raise the speed limit to 70. Going further, there is some evidence that get

If the speed limit is 65 but in practice driving 70 is still safe enough, we should raise the speed limit to 70. Going further, there is some evidence that getting rid of the speed limit actually reduces accident rates (eg. German autobahns, see https://en.wikipedia.org/wiki/Autobahn#Safety:_international_comparison https://en.wikipedia.org/wiki/Autobahn#Safety:_international...). You can look at these sort of stats in the context of the broader idea of removing explicit rules in order to increase personal responsibility and encourage safer behavior (eg. replacing stop signs and traffic lights with roundabouts, https://www.wsdot.wa.gov/Safety/roundabouts/benefits.htm https://www.wsdot.wa.gov/Safety/roundabouts/benefits.htm).