Hmmmm.... Let's start with the setting, for with the correct setting we can create a better plot :)
I was thinking, because of the fact that it's with machines and space travel that it will be in the future :)
So... Perhaps the year 2831 or something in that dirrection?
Aswell... The earth would probably not be the only planet that the humans have inhabbited i think? So we could create multiple places and settings for these planets.
If that is fine with you ofcourse :)

But to get back to the setting itself.
Because it is in the future {in my mind then} I think the buildings should be high-tech, just as the clothes, weapons etc etc.
Roads are just a mere thing for the cars that only have wheels, as for mostly the cars would probably hover trough the air. Spaceships are logical with what they do, only they are stronger and better than the ones we have in our time, for ours only are spacestations :)
So I think for the spaceships we have to look towards Star Trek, or Star Wars, for they have mostly high tech spaceships :)

Well let me know what you think about the ideas :)