ok, so let me go on a tangent here.

zombies and the "apocalypse" are literary devices used as a critique for the times that we live in. zombies are in some ways linked to globalization and the anonymity and isolation of the modern world.

the reason you don't see practical applications of surviving the apocalypse in these things is because they aren't supposed to be thriving. Exactly the opposite, they have to be just barely surviving for the the literary premise to work.

The Road is the most transparent application for this. So much of the book is centered around describing how, in the face of utter deprivation, the surrogate of the child starts to lose his humanity piece by piece by piece, and how that idea, that "flame" as it is called, is carried on by his son, who pivotally tells his father that he killed the man who stole their shopping cart and he didn't have to. This is the moment the father dies and the son is left to "carry the flame".

what these kinds of retorts do is just completely and irrevocably ignore the meaning of these things, which, especially, I can say in the road at least, are utterly moving. Children of Men is another post-apocalypse with a unique premise that falls into this category which is totally ruined by people who are trying to tie it down to some real life tautology.

so bikes in zombie apocalypse movies aren't there as a practical form of transport because in certain ways these films are critiques of how we're tethered to gas consumption, how much modern conveniences figure into our lives and then suddenly are torn away from us, how certain things we thought were obsolete suddenly become essential (think the morse code in Independence Day). People in these movies are intended to endure the lack of the things that are essential to day to day life, and that gets emphasized when something high tech and super essential for modern life becomes a block of plastic.