What strikes me about many of the photos of lost cycleways is the amount of road space we actually have. In many cases, those lost ways have been given over to car parking space.
Wandering around my local neighbourhood we were given a glimpse of the shear amount of public space normally devoted to supporting private car parking because the council are introducing a residents' parking scheme and required the roads to be cleared for a couple of days to paint the new parking zones.
Here is a neighbouring road that's normally head to toe with parked cars on both sides of the road.
And once the parking zone lines are painted, a reminder that the majority of our shared space is given over to accommodating the minority with their own cars:
Why not make it impossible for this space to be colonised by parked cars? After all, in the road round the corner, people parking cars have done the same with the pavements (and continue to do so daily with impunity):