A pasttime of mine during longer car or train journeys is to imagine new and better infrastructural links. I also like to (a a child very often) to browser maps and notice missing links, and sometimes even researching that in fact a removed rail line is indeed the reason for that multi-kilometer gently arced forest edge. During traffic jams I like to imagine metro lines between my source and destination.

Here is an anonymous person writing up rather elaborately some (actually many) of such musings: Infrastruct. In case you like infrastructure and fantasy, then have a look!