I thought this problem is solved. 50m before the tunnel, we have a big arc with a long wooden red and white sign hanging by chains at the maximum height (like t

I thought this problem is solved. 50m before the tunnel, we have a big arc with a long wooden red and white sign hanging by chains at the maximum height (like the ones in railroad crossings). if you try, you get hit hard by it. it's the most unambiguous message you can get.