Closing an area a behaviour occurred in won't stop them from "doing it". Let's face it, they should apply some serious penalties instead of this. They don't need to spend a lot of time on the bridge, nobody expects them to monitor that 100% of the time. But when they do, and if they catch someone if the penalties would be along the line of 5k+ in fines, seizures and loss -truck and fishing/hunting ban- now then you'd see a change in mentality.