That will just cause people to pay less attention when they know they will get warned before driving in too small a tunnel. I personally think things like red

That will just cause people to pay less attention when they know they will get warned before driving in too small a tunnel. I personally think things like red light with height detector or metal bars that bump into your truck and make massive amount of noise should be enough. Water curtains with lasers projecting stop sign? That's just crazy. And we all pay for the infrastructure to save people who can't be bothered to stop before red light. In my opinion if things like that start getting implemented this is just going to cause people to pay even less attention. Everybody should know to stop before red light.