Craft has instructions for making your own retro shoes from an old tire and a pair of jeans. While I don’t think these will hold up to the heavy duty running I do (at least two miles a year), they might be a fun weekend project for those so inclined.
The question, however is whether you can find unburnt tires in your corner of the apocalyptic hellscape that you would need to live in in order to decide to make your own shoes.
A few years ago a friend of mine brought me to a little town in Mexico to see the Tarahumara race. The Tarahumara are an indigenous people who live in a massive canyon and run incredible distances in sandals, called huaraches, made from old car tires. When I tried to wear a pair of these homemade huaraches, the straps chaffed the top of my feet and pulled at my leg hairs as I walked. It was terrible. But I still wanted to wear shoes made from old car tires and other upcycled materials. So I decided to make a homemade running shoe, similar to the type of shoes Bill Bowerman made for Steve Prefontaine — the original Nikes.