Driving between them takes 5 minutes in a straight line. Safely walking between them, however, is a six-hour diversion through four unrelated towns, as opposed to the 30 or so minutes it would take in a straight line. Thanks to hostile architecture, I guess.
See, there were smart people at work here. By forcing people into cars, no one will accidentally draw the sigil of Nyarlathotep on the ground. Nyarlathotep is called The Crawling Chaos for a reason.