"the PCH"? I guess that "the" is kinda optional. One thing I noticed in Fresno: In LA, we consider north as "up"--as you did "up to the 10," so one would say "I'm heading up to Fresno." But in Fresno, they say "heading up to LA" and "over to San Francisco." Makes no sense to me. Both are west of Fresno, so both could be "over," but if one is "up" shouldn't the other be "down"? And for pete's sake, LA would be "down" and Frisco "up" from Fresno.
Yeah, I say "the PCH". Probably just a colloquialism... because it should be "down to LA" and "up to San Fran". But yeah, I tend to use "up" and "down" to mean North and South, and "over" to mean East/West. PROTIP: Lake Tahoe is actually West of Los Angeles! Crazy.
I'm a little undecided on the "Foothill Freeway" example, but the ambiguity seems to hinge more on dropping the "freeway/blvd" portions than the definite article. But for Interstates, having a "the" seems a bit silly and it doesn't resolve any ambiguity that I can tell. I wouldn't say "Go north on the 15." I have multiple problems with that. There's the already discussed point of it being "Interstate 15" and not "The Interstate 15," of course. But, I'm not digging the "go north" part either. That is, Interstates are labeled with directions already. So I would say "take 15 North." "North" being part of the proper noun. I-15N spends a lot of time going northeast, and I imagine occasionally turns southward briefly as topography demands. If you're going to Vegas from San Diego, you're taking I-15N to Las Vegas. Or you could say you're going northeast on I-15. Or northeast on I-15N for extra clarity. As for up/down. I guess I generally think of it as north and south, but I don't think I take it as a direction. If someone said "go down I-15N" for example, it wouldn't bother me. I never say 'go over to' because that's going crazy overboard with the syllables. Sometimes up/down is used to refer to actual elevation changes. I know it was like that when I lived on Lake Superior. Up was away from the lake. Down was toward the lake. I guess to some extent it's like that here. People say "I'm going down to the beach," and not "over to the beach" even though it's straight to the west.
People sometimes say DCA when talking about the national airport back in DC. And there's BWI (Baltimore-Washington International).
JFK is probably the best counter-example, but then again JFK is an acronym for it's namesake. DCA and BWI are borderline, much in the same way ATL and STL are. I don't typically hear those in common parlance among frequent travelers, instead hearing "Reagan" or "DC", and "Baltimore" or "Marshall".
Fresno's airport? They tried changing the name to Fresno-Yosemite International (FYI), but most things still call it Fresno Air Terminal (FAT). Hell, half the people here don't even know where the airport is! Not sure how they miss it, it's shared with the Air National Guard, so tandem fighter jets scream out of it on a regular basis.
Add SFO to that list. As for the show, I agree with others who say it peaked in the third season or so. The show still has funny moments but it's now more or less another relationshippy sitcom that just happens to have nerds/geeks as main characters.
^ I think Tighr is talking about the airport codes widely using by people well beyond the city. Lot of people who never have been to LA know the airport as "LAX". You can't say the same for the Dallas-Fort Worth airport. BWI may be familiar to those who travel a lot, but I'll admit JFK and LAX are probably the only two that are well known to people who have never been to either cities.
Well not that anyone should be expected to know considering it isn't a very large city, but the Richmond International Airport in Virginia is commonly called the RIC around here.
It is because most of those highways/freeways were built on top of existing roads/highways that had proper names long before they had numbers. So people transitioned from saying "The ______ highway" to "The __."
Most of LA's freeways were named for where they terminated, away from downtown, that is. That's why the freeways are Santa Monica, Pasadena, Long Beach, Santa Ana, San Bernardino, Hollywood, etc. Then there's the freeways that don't go through downtown; they get other names (Foothill, San Gabriel River Freeway,etc).
In the Bay Area we had the Nimitz (880) and the Bayshore (101). We don't use "the" with the numbers for some reason.