Coincidence? Causation? In which direction? I haven't a clue. But if I'd had to pick one other region that might share our fondness for "the 290" or what have you, that would have been pretty far down the list. Get to work, word sleuths!
HIGHWAY LINGUISTICS....PART 2....Just a quick note on the Southern Californian habit of prepending "the" to highway names. We still don't know where this habit originated, but it turns out there's one other area of the continent where this is common: the Toronto/Buffalo region.