Sidevalve:
No it doesn’t. As I found out a few years ago when a car decided it wasn’t stopping and I had to swerve slightly to miss it . Bridge marked 13’3", my lorry 12’8", luckily just a scuff on the paint.That was however on a minor road. Not sure if that makes any difference.
This is why I’m always abit cautious of them even if I’m under the specified height. Seems it potentially can be a bit of a gamble as to where exactly the specified height starts and ends