They also enable mass surveillance and they also unnecessarily reduce quality of life. No one talks about the time lost to artificially low speed limits. But they do matter.
Speed cameras enable efficient enforcement of existing speed limits. They don't require 'artificially low speed limits'.
Speed cameras don't have to enable mass surveillance. The oldest ones are detect a speeding object and take two photos at a fixed interval. Cars that aren't speeding aren't recorded.
Slowing drivers isn’t a good thing. It’s just making lives worse by adding travel time when people could move faster. But my point remains - speed cameras are a backdoor surveillance method. They can be subpoenaed.
- good publicity (drivers know that speed cameras exist)
- density (high chance of passing a speed camera)
- enforcement of penalties (if fines can be ignored then they lose their deterrent effect)
- portable (so you don't know where they are ahead of time)