> In cities where space is at a premium, a bunch of people standing, or on a bicycle, will always beat out people sitting down with room for an engine and a trunk.

It depends. For example, you can theoretically fit more people into crowded bike lanes than you can into crowded streets. But around here at least, bike lanes don't get a lot of people. I lived by one for years that I don't think I ever saw a bicycle on once. But even when not in use, all of that space is still being set aside for cyclists.