[AndrewC]

If asphalt highways were the only way, you'd have a point,

True, but when your upright example leaves Dallas and arrives in Detroit on his own volition and without "help", you'd have a point.

[general_re]

Well, the guy that went first got to Detroit. This guy, he wasn't really headed for Detroit in the first place - he just set out walking. On the way, he faced the same sort of hurdles that the first guy faced, and thereby ended up wandering in a pretty similar direction. Of course, in the end, he wound up in Windsor, Ontario, which is pretty close to Detroit, but not exactly the same as Detroit.