I know a coach driver who also worked on occasions delivering moblie cranes. One busy day in E. London he hit the underside of a rail bridge. All traffic and trains stopped - chaos. He swore he'd checked the stated bridge height against the declared height of his crane and it was OK. No-one believed him, until they checked the actual height of the bridge - and it was inches less that its stated height. It turned out that repairs to the road surface had been done by adding tarmac, rather than replacing it - so he wasn't prosecuted. But he wasn't asked to deliver any more cranes.