Main Route/Main Route concurrencies

[hotdogPi]

I-80 and I-90 through half of OH and almost all of IN. In fact I-80 is useless in IN, as it overlaps other interstates all the way through the state.

And I-80 splits from those overlaps on both sides. East of Cleveland and west of Chicago I-80 is by itself so is it suppose to be like I-76, I-84 and I-88 and have a gap in the middle of its route?

76, 84, 86, and 88 are numbers that have two different, unrelated Interstates associated with them. Western I-76 and eastern I-76 are separate, not different parts of the same route with a gap, and the same is true with 84, 86, and 88. I don't consider the new I-87 in North Carolina legitimate, but it would be the same with that.

I-49 and I-69 do have gaps, as does I-74 within North Carolina. I-74 between Ohio and North Carolina is debatable.

About I-80: I-80 is signed just as well as I-90 is when they are overlapped. There is no gap. You could ask the same about I-90 instead of I-80.

I-75/85 in Atlanta.
I-80/90 from about 40 miles west of Cleveland to Lake Station, Indiana.

Those are the only two that come to mind right now.

Both are already mentioned in Reply #3.

[TheStranger]

Though brief, I-5 and I-10 have a (somewhat poorly signed) concurrency along the portion of the Golden State Freeway in East Los Angeles south of where historic US 99 split off to follow the San Bernardino Freeway.

[Roadgeekteen]

Though brief, I-5 and I-10 have a (somewhat poorly signed) concurrency along the portion of the Golden State Freeway in East Los Angeles south of where historic US 99 split off to follow the San Bernardino Freeway.

I think I-10 ends and begains at the 2 sides of the concourrency.

[Charles2]

US routes that come to mind:

US-11 and US-70 in Knoxville, also 11, 25 and 70
US-31W and US-60 in Louisville
US-11 and US-80 in west Alabama leading to Meridian, MS

(Yes, I know that most, if not all of these have been supplanted by Interstate highways...)

[JKRhodes]

US 180 and US 191 run concurrent for 55 miles from Alpine, AZ to St. Johns, AZ.

They're both 3di, but if memory serves, both significantly longer than their "parent" routes.

[Flint1979]

US 180 and US 191 run concurrent for 55 miles from Alpine, AZ to St. Johns, AZ.

They're both 3di, but if memory serves, both significantly longer than their "parent" routes.

The way I see it is that US 191 should be US 91 not a three digit. US 180 I believe is about 60 miles longer than US 80 and doesn't even meet up with US 80 anymore. US 191 no longer meets up with US 91 either. This has happened a lot with US highways though.

[CNGL-Leudimin]

There are even a few that are orphaned: US 138, US 166, US 266 and US 199. The first one is the most notable case, as US 38 was killed by US 6 early in the history of US routes, but US 138 remains to this day.

Back on topic, a historical one: US 60 and US 70 between Globe AZ (current US 70's Western terminus) and Beaumont CA IIRC. There was even a concurrency of US 60, US 70 and US 80 (and US 89 as well, but that doesn't end in 1) into Phoenix, of which only US 60 remains.

[Roadgeekteen]

US 180 and US 191 run concurrent for 55 miles from Alpine, AZ to St. Johns, AZ.

They're both 3di, but if memory serves, both significantly longer than their "parent" routes.

They are not main roads.

[JKRhodes]

US 180 and US 191 run concurrent for 55 miles from Alpine, AZ to St. Johns, AZ.

They're both 3di, but if memory serves, both significantly longer than their "parent" routes.

They are not main roads.

clarify...  do you define a main road by  route length? Number of lanes?

[hotdogPi]

clarify...  do you define a main road by  route length? Number of lanes?

Based on the OP,

Like a I-x0/x0, or I-x5/x5, or I-x0/x5 or US x1/x1, you get the idea

he seems to consider I-x0, I-x5, US x0, or US x1 (2-digit only) as "main", plus (possibly) US 2 and (definitely) US 101, as these were the ones intended to be major. It is unclear if mixing one Interstate with one US route is allowed or not.

[Flint1979]

US 180 and US 191 run concurrent for 55 miles from Alpine, AZ to St. Johns, AZ.

They're both 3di, but if memory serves, both significantly longer than their "parent" routes.

They are not main roads.

clarify...  do you define a main road by  route length? Number of lanes?

Based on the route number.

[hbelkins]

US 180 and US 191 run concurrent for 55 miles from Alpine, AZ to St. Johns, AZ.

They're both 3di, but if memory serves, both significantly longer than their "parent" routes.

They are not main roads.

clarify...  do you define a main road by  route length? Number of lanes?

Based on the route number.

This.

Roadgeekteen may not know this, but when the US highway system was developed, the major coast-to-coast or border-to-border (or in some cases, not quite but close enough) routes ended in 0 (even) or 1 (odd). US 101 was considered to be a major route despite having three digits.

When the Interstate system was designed, the major routes were designated as ending in 5 for north-south routes and 0 for east-west routes.

[Flint1979]

US 180 and US 191 run concurrent for 55 miles from Alpine, AZ to St. Johns, AZ.

They're both 3di, but if memory serves, both significantly longer than their "parent" routes.

They are not main roads.

clarify...  do you define a main road by  route length? Number of lanes?

Based on the route number.

This.

Roadgeekteen may not know this, but when the US highway system was developed, the major coast-to-coast or border-to-border (or in some cases, not quite but close enough) routes ended in 0 (even) or 1 (odd). US 101 was considered to be a major route despite having three digits.

When the Interstate system was designed, the major routes were designated as ending in 5 for north-south routes and 0 for east-west routes.

Right. US 101 is treated as a two digit route.

SAMSUNG-SM-J727A

[TheStranger]

Though brief, I-5 and I-10 have a (somewhat poorly signed) concurrency along the portion of the Golden State Freeway in East Los Angeles south of where historic US 99 split off to follow the San Bernardino Freeway.

I think I-10 ends and begains at the 2 sides of the concourrency.

California legislative route definitions don't really have any bearing on how an Interstate is defined by FHWA (especially since there is that not-quite-I-10 segment of the San Bernardino Freeway, which is officially part of the California definition of Route 10, between US 101 and I-5...originally built as US 60/70/99). 

[JKRhodes]

US 180 and US 191 run concurrent for 55 miles from Alpine, AZ to St. Johns, AZ.

They're both 3di, but if memory serves, both significantly longer than their "parent" routes.

They are not main roads.

clarify...  do you define a main road by  route length? Number of lanes?

Based on the route number.

This.

Roadgeekteen may not know this, but when the US highway system was developed, the major coast-to-coast or border-to-border (or in some cases, not quite but close enough) routes ended in 0 (even) or 1 (odd). US 101 was considered to be a major route despite having three digits.

When the Interstate system was designed, the major routes were designated as ending in 5 for north-south routes and 0 for east-west routes.

Right. US 101 is treated as a two digit route.

SAMSUNG-SM-J727A

So.....
101 is 3di but gets a pass due to length.

191,  spanning from Mexico to Canada, doesn't count...

180,  which runs from greater Fort Worth to the grand canyon, also doesn't count...

Cool.

[Flint1979]

US 101 doesn't get a pass because of it's length it get's a pass because it's a main US highway and the north-south main US highways all end in a 1. There already was a US 99 so that number couldn't be used anyway. They could have used US 91 instead of US 101 but then they would lose four valuable highway numbers (93, 95, 97 and 99). AASHTO made an exception to its two-digit rule. Thus, US 101 is treated as a primary, two-digit route with a "first digit" of 10, rather than a spur of US 1, which is located along the east coast, on the opposite side of the U.S. Thus US 101, not US 99, is the westernmost north-south route in the U.S. Highway System.

[hbelkins]

US 101 gets its pass due to position, not length.

As for US 191, remember that the portion south of I-40 used to be US 666, long before the section north of Gallup was renumbered to 491.

[bassoon1986]

Historically US 51 and US 61 were routed together from LaPlace into downtown New Orleans at their southern termini.


iPhone

[cl94]

US 1 and US 2 have a concurrency through Houlton, ME (US 2 is generally considered to be major). US 1 is also concurrent with US 50 in Washington, DC and US 90 in Jacksonville, FL.

Staying with US 1, US 1 has concurrencies with I-95 south of Boston and across the GW Bridge.

[Beltway]

If one were to depart from the idiom of nothing but "0" and "5" Interstates as "main" routes and used traffic and connectivity as criteria, it would be safe to say that the following routes could be considered "main":  for N-S routes, 29, 59, 81, and 87 (the real one in NY, not the pretender down south); for E-W routes, 44, 64, the western 84, and 94 (funny how the 4's take up the slack for the 0's).  49 will certainly join the list when complete -- and possibly 69 well into the future.  Because of truck traffic, I'd almost put 57 on the list; but in reality it functions more as a "55E".

Going by that list, I-77 could certainly be added to it.  That was originally promoted as the Great Lakes to Florida Highway.  It indeed does that, with its connections to I-26 and I-95 and I-79.  Connects Cleveland, Pittsburgh and Erie and Buffalo to Florida.  In and of itself it is 613 miles long, and serves Columbia SC, Charlotte NC, Charleston WV, Akron OH and Cleveland.

[PHLBOS]

Staying with US 1, US 1 has concurrencies with I-95 south of Boston and across the GW Bridge.

Those aren't the only locations where US 1 is concurrent w/I-95.

[roadman65]

Did anyone mention I-20 & 59 through MS and AL?

Also the infamous US 1 & 9 in NJ that NJDOT gave it single shield like it is one route rather than two separate US routes as it really.  It is a main route not by long distance as I-95 and the NJ Turnpike take that title, but regionally the one and nine is important as it serves many cities like Rahway, Linden, Elizabeth, Newark, and Jersey City and used heavily by trucks delivering along the Chemical Coast and all the industrial plants along the Arthur Kill.

[hotdogPi]

Did anyone mention I-20 & 59 through MS and AL?

Also the infamous US 1 & 9 in NJ that NJDOT gave it single shield like it is one route rather than two separate US routes as it really.  It is a main route not by long distance as I-95 and the NJ Turnpike take that title, but regionally the one and nine is important as it serves many cities like Rahway, Linden, Elizabeth, Newark, and Jersey City and used heavily by trucks delivering along the Chemical Coast and all the industrial plants along the Arthur Kill.

How are you defining "main route" to include I-59?

[dvferyance]

I would consider I-90/I-94 both in Wisconsin and Chicago to be a main route concurrencies even though I-94 does not end in zero it's still quite major being the longest non zero interstate.

[wxfree]

US 101 is not a child of US 1.  I think of it as being US "ten-one," with 10 the the tens digit place.  It's an extra-wide two-digit number.  It doesn't make actual sense, but it maybe doesn't make sense less than having the most distant parent-child association possible doesn't.  I've thought about the idea of "US 101-ing" the Interstate system, with I-105 running along the East Coast (not to get fictional, but just proportionately nonsensical).