a) They are too expensive.

b) There isn’t enough room.

And yet, in the recently we’ve seen a complete system of Olympic lanes spring up almost overnight, including new signage and road markings, and despite complaints from some motorists.

If the room and the money exists for those, despite them only being required for a few weeks, the only conclusion can be that infrastructure changes don’t happen because:

c) There isn’t the political will, despite the kind of obvious benefits shown in a blog post like this.