While it is the responsibility for police to enforce the law, why waste their valuable time and endanger their lives on routine traffic stops for speeding? Why aren't their automatic speed monitors along all the highways of the USA? If weigh stations can use radar to detect issues with trucks and 'weigh as they go' there is no reason why radar can't be used to monitor speeds on highways.
The income to the State and Local governments would be helpful and effortless. The traffic cams can send the tickets and the maintenance can do regular calibration tests. What is everyone waiting for? These should be high priority projects and more than shovel ready. It expands the tax base as well as enforcing the laws.
