I am pretty confident an abnormally low bridge would have fewer accidents — the fact that it looks like it's just high enough doesn't help matters. Perhaps the

I am pretty confident an abnormally low bridge would have fewer accidents — the fact that it looks like it's just high enough doesn't help matters. Perhaps the simplest solution is to introduce a light hanging (eg rubber) plate to make the underpass appear even shorter so people do stop and look at the signs.