The second part there is the key. Bikes work just fine on roads built for cars and building bike lanes is dirt cheap compared to pretty much any other kind of i

The second part there is the key. Bikes work just fine on roads built for cars and building bike lanes is dirt cheap compared to pretty much any other kind of infrastructure project. You do, however, need the political will to actually take that space from cars and reallocate it to bikes and pedestrians. In urban areas that are already dense this can be done without any significant infrastructue investments by simply changing how the traffic patterns work on existing roads. A good example of this is Barcelona's "superblocks": https://www.vox.com/energy-and-environment/2019/4/9/18300797/barcelona-spain-superblocks-urban-plan https://www.vox.com/energy-and-environment/2019/4/9/18300797...