Funny you should mention speed limits since, like marijuana prohibition, they exist largely to give police something to do. We don't need to speculate on what would happen if we got rid of speed limits since it has been tried in several countries, including ours, and the roads were safer without the speed limits. At present, there is a trend in Europe to eliminate most road signs and traffic lights. Every town that has tried it has seen reduced accidents and smoother traffic. It seems that trusting people to figure things out for themselves and holding people liable only for tangible harm they cause works better than top-down micromanagement of behavior by the state. Why do I need to explain this to conservatives?