I'm still surprised automated enforcement isn't more widespread. Where I live red light cameras are at almost every major intersection, speed cameras are on school roads and construction sites, school busses have ticketing cameras. But on the highway it's cops in cars (and supposedly aircraft) with radar/lidar. Thirty minutes a day on the highway is enough to know there's plenty of people undeterred from driving 40+ mph over the limit (20 mph over is enough to suspend your license after two strikes). I'd guess the 'math' (money, politics, initiative) doesn't work out, or maybe the tech is just rolling out very slowly and hasn't made it here yet.