Please see the attached image. When I try to build a bridge from the upper-right slope, it succeeds and the southern bridge end is dangling. I believe this should not be allowed.
This was possible for a very long time and has never been fixed ... It was an easter egg like the harbour tunnel, albeit it should go now.
this is a bug, the bridge is one tile too long.
should be fixed in 2772.
This dated even back to the time before bridges at vertical slopes. But I agree, it shoudl go. (It did work also without road on the left slope previously.)