Comment by mytailorisrich

> and a single narrow main lane each way so cars can't go very fast

You're underestimating French drivers here ;) . Also on that picture the main lane is not considered narrow at all in France/Europe, it's quite comfortable to speed.

The only way to limit speed is speed cameras and speed bumps (both are also becoming ubiquitous in the UK).

China is what I imagine the US with bike lanes would look like.