To address the original question, around here in southern NH and I think in MA, the common name for most roads seems to be “route” and the number regardless of whether it’s an interstate, US route or state road. Luckily the numbers seem to be unique in any particular area.
I notice that NH 13 conveniently joins MA 13 at the border. Is that a common thing that states try to do, i.e, match up the numbers where numbered state roads meet?
Yep, this is the case in the Boston area. In fact, you can find signs to Route (Interstate) 95 and the like. Methinks this is an old convention that stuck. Younger folks call the roads by their type and number, “I-93,” or just plain old “93.”
Not often. The numbering schemes for state highways often vary so unless it’s an interstate or US route, there’s little attempt at highway number continuity when a road crosses the border from one state into another. However, it does happen occasionally. For example, if you go keep going east on Idaho State Highway 200, it will become Montana State Highway 200, North Dakota Highway 200, and Minnesota State Highway 200.
I’m sure it must be a coincidence, but it happens across international crossings once in a while, too. South of San Antonio on I-35, you can exit US-57, which becomes Mexican Highway 57 and 57D, which will bring you all the way to Mexico City and beyond.
In and around Philadelphia
I-276 - The Turnpike
I-76 (West of King of Prussia) - The Turnpike
I-76 (East of King of Prussia) - The Schuykill
I-676 - The Vine Street
I-476 (South of Plymouth Meeting) - The Blue Route
I-476 (North of Plymouth Meeting) - The Northeast Extension
I-95 is called 95. I am told that the name is the Delaware Expressway but I have never heard anyone use that.
For other roads
US 1 (north of the Schuykill) - When its an expressway, I think people call it Route 1. Once you get into Northeast Philly, its the Boulevard (short for the Roosevelt Boulevard)
US 1 (part South of the Schuykill) - City Avenue (Everyone calls it City Line)
After I moved out here, I think it took me a month to understand the traffic report on the radio.
It’s actually not that coincidental. After the north-south US Routes were designated, some of the Canadian provinces decided to use the same numbers for many of the north-south highways that crossed the border (e.g., US 97 becomes BC 97). That way you reduce motorist confusion.
Oahu, Hawaii
As far as I know, everyone has always called the highways either H-1, H-2, or H-3.
Exit 5, Exit 7, wasn’t sure where it actually left. I knew it was somewhere in that space.
Otherwise, all generally correct, but at my workplace in Merrimack NH, it’s referred to as “The Turnpike” if you’re heading north from here, or headed south, but not leaving the state. If you’re going down to MA, folks generally say “Get on 3 south…” When I started working here, I hadn’t had much experience with the area, other than driving through from 495 to 93 headed into Northern NH. The “Old 3” comment is very fair, though it’s the only 3. Nobody wants to drive on Old 3, as it’s a local road, but sometimes that’s where you’ve got to go. You’d never actually leave 3 at exit 7 to travel it’s length. North of there, it’s not a ‘highway’ in the same sense as it is if you learned the route with a Northern MA perspective.
But I agree it’s confusing, and very local knowledge dependent, if you want to understand the directions, but it’s better than some directions I’ve gotten! “Turn left where Mabel used to live, then 3 miles up past the Benson rock to the middle logging road. Can’t miss it.” 
I live down in the Joliet/Plainfield area and it is kind of amusing to know I say “I’m taking 55 to Bolingbrook” and “I’m taking the Stevenson into the city” despite it technically being the same stretch of asphalt.
Likewise, I never hear anyone refer to 355 as the “North-South Tollway”.
Parkway East or West depending on the side of the city (Pittsburgh) and not the direction of travel.
Parkinglot East or West if you have to drive them at rush hour.
Here (Detroit) it’s either the number by itself (696) or the name with The (The Lodge). Some freeways are overwhelmingly known one way or the other. Calling a non-Interstate by its number tends to be unusual.
M-24… I can’t even remember the name of it. Maybe… Lapeer Rd. or something?
And then there’s M-29 and M-25. Just a lot easier to call them that than all of the different names they have along their course.
Finally, M-59, even the “Hall Rd.” portion, is referred to just as much by the moniker M-59 as Hall Rd.
As a lifelong central Texan, I’ve always favored IH-35.
And then there’s Loop 1, pronounced MoPac.
I get what you’re saying now. I misunderstood your first post and thought you meant that the turnpike name didn’t start until exit 5 when you’re heading north and the part between 1 and 5 was officially just route 3. I wasn’t trying to nickpick about the split being at 5 or 7.
I work in Bedford and several times I’ve heard people on the phone giving directions like “come up route 3 until exit 12, then you’ll get onto umm… another route 3”. I’ve also heard “yeah this road used to be route 3, some of the old signs are still there”.
The area between The Hooksett Tolls & the NH/MA border in Nashua is confusing with the route names. The same bit of highway (meaning you don’t exit with a great turn), changes from Rt 3, to the Everett Turnpike, to 293, to 93. You don’t have to do anything to start on the “new route,” but it can suddenly have a different name. Explaining it can be great fun!
I didn’t do a very good job in my first post. It’s a tough thing to explain, and often depends on who you’re talking to when giving directions or describing a location. I still get baffled with the 111/111A/101/101A/ and associated bypasses a bit west of Merrimack. I’m always like “it’s one of those.”
WE don’t really have any freeways near us. The closes we get are US highways that have been split. And we call them either the number by itself, or we put Highway in front of it. We also tend to refer to the part of the highway that was redesigned to go around the town as a Bypass.
What’s interesting is that the main highway running the length of NZ is called State Highway 1 - and that’s what everyone calls it (or at least did when I lived there). Not “The One” or anything. Occasionally it’s shortened to “State Highway” (We’ll probably take the State Highway down towards Ashburton then turn off towards Methven), IIRC.
Here in Houston, they decided to give names to all the freeways. I-10 on the west side is the Katy Freeway; on the east side, it’s unimaginatively called the East Freeway. I-45 on the north side is the North Freeway, but on the south side, it’s the Gulf Freeway.
Here in South Africa (at least in Cape Town) it’s always “the Xy”, so “the N2” or “the M5”. But they mostly have names as well, and it seems like older people prefer the names. We manage to make things slightly more confusing by having a highway that’s called the “Simon van der Stel Freeway” officially and on the maps, but that everyone calls the “Blue Route”, for reasons lost in the mists of time.
Yeah, I do like the IH convention. I think it’s uniquely Texan.
The mess of Texas highway nomenclature leaves much to be desired. SH, FM, RM, RR, and so forth? We use numbers mostly. US-183 is always just “183,” as is “290.”
Loop 1 (which isn’t even a loop) is MoPac, which I believe does not have Missouri Pacific trains on the railway that the road is named for. Go figure. Then we’ve got 130, which in some quarters is called the Mo-Kan Expressway.
Some cool info on what could have been - Austin freeways, here.