Do Dogs Ever Return After They Run Away??

Sometimes... If nothing happens to them, and they can find their way back they do.  But don't give up checking all the local shelters (not just the one closest to you).. Even if it's been awhile.. Check weekly... Sometimes someone else takes them in for awhile, before they leave there and get picked up.
Keep looking, contrary to popular belief, not all dogs are great at finding their way home... Sometimes they go out for a good time and actually get lost.