Banishing pedestrians underground so the cars can have the surface is a little bit backwards though.

There are certainly situations where a pedestrian bridge or underpass is the only reasonable solution, but it shouldn't be the default solution. And if you have to build a pedestrian underpass, at least make it spaceous, inviting and easily accessible, and not dark and claustrophobic.

I'm fairly certain the underpass in this picture is quite old, and it passes under what used to be the main road to the north before the ring-road was finished.