Wasn't meant to read as hubris, I genuinely was curious (if a little unclear). FWIW I have read about this at length generally at a local level, living and wor

Wasn't meant to read as hubris, I genuinely was curious (if a little unclear). FWIW I have read about this at length generally at a local level, living and working next to a couple of bridges with this issue. A high tech approach has been tried and abandoned with these bridges as they were (fatally) not effective (though not this high-tech). I naturally assumed there was some particular reason for the tunnel. I read the rest of the thread before I commented, the ones you point out were written after, and they do indeed go some way toward explaining that particular issue at that particular tunnel. The original post did not explain anything but the bad road design. While we are giving friendly advice, your comments may be better received if you gave them in a spirit of generosity, as I have taken yours, rather than jumping straight to judgements and epithets.