De facto X0/X5 Interstates

[Hwy 61 Revisited]

I've noticed something in the Interstate grid. It looks like some routes ending with 4 (94, 64, 84 west) essentially act as X0 routes, serving major corridors missed by the actual X0s, often more important than the cities hit by the actual X0s. Something else happens with Interstates like X9s (29, 59, 49, 69) and X1s (81, 71, 11 in the future). Meanwhile, some X0s and X5s (30, 45) aren't exactly major regional connectors. Isn't that somewhat strange?

[Max Rockatansky]

I-30 seems off to me given how short it is.  I-32 or I-28 seemingly would have been just of a good of fit?  Similarly I-45 doesn't really seem to fit the bill of an X5 Interstate in terms of distance...major destinations yes though.

[cpzilliacus]

I-81 seems more like a "real" long N-S interstate highway than I-85 does.  And I-81 is longer too. 

But I-81 stays far enough west to avoid really large metropolitan areas, unlike I-85 through places like Atlanta, Georgia; Charlotte, North Carolina; Research Triangle, North Carolina; Greater Richmond Region, Virginia (though I-85 does not make it to Richmond); and Montgomery Alabama.

[US 89]

I've noticed something in the Interstate grid. It looks like some routes ending with 4 (94, 64, 84 east) essentially act as X0 routes, serving major corridors missed by the actual X0s, often more importantthan the cities hit by the actual X0s.

You're going to leave western I-84 off that list? It serves Portland, Boise, and the greater Salt Lake City area, and it's pretty much the route from the Pacific Northwest to anywhere south of I-90.

[Hwy 61 Revisited]

I've noticed something in the Interstate grid. It looks like some routes ending with 4 (94, 64, 84 east) essentially act as X0 routes, serving major corridors missed by the actual X0s, often more importantthan the cities hit by the actual X0s.

You're going to leave western I-84 off that list? It serves Portland, Boise, and the greater Salt Lake City area, and it's pretty much the route from the Pacific Northwest to anywhere south of I-90.

Sorry, brain-fart.

[sparker]

I've noticed something in the Interstate grid. It looks like some routes ending with 4 (94, 64, 84 west) essentially act as X0 routes, serving major corridors missed by the actual X0s, often more important than the cities hit by the actual X0s. Something else happens with Interstates like X9s (29, 59, 49, 69) and X1s (81, 71, 11 in the future). Meanwhile, some X0s and X5s (30, 45) aren't exactly major regional connectors. Isn't that somewhat strange?

A lot of that had to do with the original aim of not duplicating US highway numbers and Interstate numbers in the same state -- effectively keeping 50 and 60 off the list.   As "substitute" routes for those missing numbers, one could consider both I-44 and I-64 -- long-distance regional arteries hosting transcontinental traffic -- as the effective 50 and 60.   Also, quite a few folks think that the section of I-94 between Billings, MT and Tomah, WI should have been the real I-90, since it goes through the Twin Cities, arguably the major metro area of the upper Midwest/Plains region -- and that I-90 via Sioux Falls and Rapid City should have been something like I-86, since it features less aggregate traffic.   But the observation about E-W Interstates ending in "4" is pretty accurate; since the "end" of suffixed routes ca. 1980, no less than four end up hosting transcontinental and major interregional traffic (44, 64, 84/west, 94).  Even the shorter I-24 serves as a connector between disparate regions (Midwest and Deep South).  We'll leave the "pretender to the throne" I-74 out of this mix for the time being! 

[Beltway]

A lot of that had to do with the original aim of not duplicating US highway numbers and Interstate numbers in the same state -- effectively keeping 50 and 60 off the list.   As "substitute" routes for those missing numbers, one could consider both I-44 and I-64 -- long-distance regional arteries hosting transcontinental traffic -- as the effective 50 and 60.   

For north-south x5 routes, though, all exist -- 5, 15, 25, 35, 45, 55, 65, 75, 85, 95.

[GaryV]

A lot of that had to do with the original aim of not duplicating US highway numbers and Interstate numbers in the same state -- effectively keeping 50 and 60 off the list.   As "substitute" routes for those missing numbers, one could consider both I-44 and I-64 -- long-distance regional arteries hosting transcontinental traffic -- as the effective 50 and 60.   

For north-south x5 routes, though, all exist -- 5, 15, 25, 35, 45, 55, 65, 75, 85, 95.

And it works because the US highways used x1 as their major cross-country routes, so there was less chance of interference with usually shorter US-x5 routes.  And also I-45 being only inside Texas helps.

[sparker]

A lot of that had to do with the original aim of not duplicating US highway numbers and Interstate numbers in the same state -- effectively keeping 50 and 60 off the list.   As "substitute" routes for those missing numbers, one could consider both I-44 and I-64 -- long-distance regional arteries hosting transcontinental traffic -- as the effective 50 and 60.   

For north-south x5 routes, though, all exist -- 5, 15, 25, 35, 45, 55, 65, 75, 85, 95.

And it works because the US highways used x1 as their major cross-country routes, so there was less chance of interference with usually shorter US-x5 routes.  And also I-45 being only inside Texas helps.

The lack of a US 55 after the '30's didn't hurt either regarding the N-S 5's either.  In addition, the basic shape of the US as a laterally-biased rectangle allowed a bit more spread as regards number distribution.  But from that point on, it was an "open market" regarding the importance of specific odd-numbered Interstates not divisible by 5.  Some were configured as major interregional arteries (29, 59, 77, 81), while many others simply served as regional connectors.  That being said, WI still managed to F.U. the upper Midwest grid arrangement with I-43 (the last to be designated of the '68 additions); but to be fair, back in the early '70's with the revamped rules requiring a "bottom-up" designation process few (outside of IL in the '80's and '90's) expected much in the way of new Interstate corridors until the ISTEA and NHS legislation in the nineties. 

[Hwy 61 Revisited]

Also, quite a few folks think that the section of I-94 between Billings, MT and Tomah, WI should have been the real I-90, since it goes through the Twin Cities, arguably the major metro area of the upper Midwest/Plains region -- and that I-90 via Sioux Falls and Rapid City should have been something like I-86, since it features less aggregate traffic.

And it even shows up as the preferable way on Google Maps, despite passing through the Twin Cities and such.

[Flint1979]

Also, quite a few folks think that the section of I-94 between Billings, MT and Tomah, WI should have been the real I-90, since it goes through the Twin Cities, arguably the major metro area of the upper Midwest/Plains region -- and that I-90 via Sioux Falls and Rapid City should have been something like I-86, since it features less aggregate traffic.

And it even shows up as the preferable way on Google Maps, despite passing through the Twin Cities and such.

Funny that when I looked for Billings to Tomah it's 14 hours, 42 minutes and 1,009 miles taking I-94 and 14 hours, 48 minutes and 987 miles taking I-90 via the US-212 shortcut.

But going Tomah to Billings it's 14 hours, 47 minutes and 1,010 miles taking I-94 and 14 hours, 36 minutes and 988 miles taking I-90 and again via the US-212 shortcut.

[bing101]

I-7/ I-9 proposed freeway from Ridge Route to Sacramento (aka CA-99) is simply a defacto X-5 if it was approved.

[Hwy 61 Revisited]

I-7/ I-9 proposed freeway from Ridge Route to Sacramento (aka CA-99) is simply a defacto X-5 if it was approved.

Let's hope it extends up to Tri-Cities or so.

[MikeTheActuary]

I-30 seems off to me given how short it is.  I-32 or I-28 seemingly would have been just of a good of fit?  Similarly I-45 doesn't really seem to fit the bill of an X5 Interstate in terms of distance...major destinations yes though.

Not I-28.  It'd be out-of-place as compared to I-22, I-24, and I-26. 

[hotdogPi]

I-30 seems off to me given how short it is.  I-32 or I-28 seemingly would have been just of a good of fit?  Similarly I-45 doesn't really seem to fit the bill of an X5 Interstate in terms of distance...major destinations yes though.

Not I-28.  It'd be out-of-place as compared to I-22, I-24, and I-26. 

Then it would have to be below 20, and it's clearly north of I-20.

[Max Rockatansky]

I-30 seems off to me given how short it is.  I-32 or I-28 seemingly would have been just of a good of fit?  Similarly I-45 doesn't really seem to fit the bill of an X5 Interstate in terms of distance...major destinations yes though.

Not I-28.  It'd be out-of-place as compared to I-22, I-24, and I-26. 

Then it would have to be below 20, and it's clearly north of I-20.

Or an X20 or X40.  That would mean reassigning something to I-530 also.  I still think I-30 is important enough to justify a 2D designation much like I-17 since they connect X0 Interstates. 

[Hwy 61 Revisited]

I-66 should honestly be a 3di. It's one of the shortest Intersates, and it's shorter than many Interstate spurs (135, anyone?).

[Konza]

If I-70 had been I-60, would it have helped anything?

The only state where I could see this would have been confusing is Missouri.  Yes, US 60 and I-70 also both enter Illinois and West Virginia, but US 60 is in Illinois is for less than a mile through a place few bother to travel, and I-70 passes through only the Northern Panhandle of Vest Virginia.

Even in Missouri, the routes are parallel and over 100 miles apart.

Subtract 10 from I-64, I-66, and I-68, and the only issue is the relatively recent extension of I-64 into Missouri.

Thoughts?

[Rothman]

Fictional territory.

[Hwy 61 Revisited]

You know I-45 is a major interstate when a "minor" corridor like I-69 (hehe) has more mileage.

[Max Rockatansky]

You know I-45 is a major interstate when a "minor" corridor like I-69 (hehe) has more mileage.

I-69 used to be just a regional connection to the Canadian border in Port Huron until all these planned expansions started.  Driving that Interstate in High School I never would have thought it would be any more significant other than the freeway I took home from the Chicago area.

[sparker]

You know I-45 is a major interstate when a "minor" corridor like I-69 (hehe) has more mileage.

I'll reiterate what I've said previously -- the concept of 5's and 0's being the "major" routes was highly oversold back in the early days ('57-'58) of deciding designations -- and a number of major cities pissed and moaned because they weren't either sited on one or, even more often, at the junction of a 0 and 5.  The first numbering iteration had what is now the western I-84 as I-82 (the present I-82 connector wasn't even a corridor then), but Portland demurred because at the time they, through their Oregon congresspeople, expressed the wish to have a x0 heading their way.  Houston also wanted to be at a "double major" junction, being close to the million-population mark at the time, and I-35 was slated to head down US 81 to Austin and San Antonio from DFW.  So the numbering system was "tweaked" to accommodate them.  Remember that back then the system was tacitly assumed to be a "one-shot" deal;  significant future additions were not even seriously considered -- 40K worth of network was enough to bite off in one big and expensive chunk!  So the "long single-ended suffixed designation" was instituted, yielding I-80N for the entire Utah-Portland NW server; likewise, when I-80 was shifted from the PA TPK, which had split near Harrisburg into 80N to New York Metro and 80S to Philadelphia, north to the present alignment 80S was simply retained, splitting off from the main near Youngstown, OH. (both the original I-80 and later I-80S had a significant multiplex with I-70 over the turnpike).  And Houston got I-45 over what was to be a regional connector, accounting for the relative shortness of its length.  Frankly, the Midwest just didn't have that many available corridors under the original Interstate schematic, and winding I-35 around to accommodate as many midwestern metro areas as possible created a problematic situation, designation-wise.  So I-29 ended up as a major route (it might have actually been I-35, with KC-Duluth being I-45 if only Houston hadn't whined about their status).  Of course, down the line the suffix concept was rethought; and the current numbering scheme commenced with I-80S gradually being supplanted by I-76 starting back in 1964 (mirrored a dozen years later with the Denver-Nebraska I-80S becoming I-76 -- with that number derived from the 1976 Colorado centennial celebration).  CA also dealt with their I-5 split routes in 1963 as a prelude to their general in-state renumbering a year later.  Then, when AASHTO, with FHWA backing, decided to eliminate the suffixes in the late '70's (with the I-35 DFW/Twin Cities splits being "grandfathered" in), the various suffixes (on I-15, the I-35 Salida branch, I-70, and I-80) were changed to what they are today.   But by that time, many cities such as Portland had rethought their commitment to freeways in general, so most of that activity went uncontested.   So what is on the ground today reflects shifting priorities over the years -- from early accommodation of various cities' wishes to rethinking and rationalizations of those decisions later down the line -- which has led to some unusual (albeit often necessary) designation choices with later system additions. 

[Hwy 61 Revisited]

You know I-45 is a major interstate when a "minor" corridor like I-69 (hehe) has more mileage.

I'll reiterate what I've said previously -- the concept of 5's and 0's being the "major" routes was highly oversold back in the early days ('57-'58) of deciding designations -- and a number of major cities pissed and moaned because they weren't either sited on one or, even more often, at the junction of a 0 and 5.  The first numbering iteration had what is now the western I-84 as I-82 (the present I-82 connector wasn't even a corridor then), but Portland demurred because at the time they, through their Oregon congresspeople, expressed the wish to have a x0 heading their way.  Houston also wanted to be at a "double major" junction, being close to the million-population mark at the time, and I-35 was slated to head down US 81 to Austin and San Antonio from DFW.  So the numbering system was "tweaked" to accommodate them.  Remember that back then the system was tacitly assumed to be a "one-shot" deal;  significant future additions were not even seriously considered -- 40K worth of network was enough to bite off in one big and expensive chunk!  So the "long single-ended suffixed designation" was instituted, yielding I-80N for the entire Utah-Portland NW server; likewise, when I-80 was shifted from the PA TPK, which had split near Harrisburg into 80N to New York Metro and 80S to Philadelphia, north to the present alignment 80S was simply retained, splitting off from the main near Youngstown, OH. (both the original I-80 and later I-80S had a significant multiplex with I-70 over the turnpike).  And Houston got I-45 over what was to be a regional connector, accounting for the relative shortness of its length.  Frankly, the Midwest just didn't have that many available corridors under the original Interstate schematic, and winding I-35 around to accommodate as many midwestern metro areas as possible created a problematic situation, designation-wise.  So I-29 ended up as a major route (it might have actually been I-35, with KC-Duluth being I-45 if only Houston hadn't whined about their status).  Of course, down the line the suffix concept was rethought; and the current numbering scheme commenced with I-80S gradually being supplanted by I-76 starting back in 1964 (mirrored a dozen years later with the Denver-Nebraska I-80S becoming I-76 -- with that number derived from the 1976 Colorado centennial celebration).  CA also dealt with their I-5 split routes in 1963 as a prelude to their general in-state renumbering a year later.  Then, when AASHTO, with FHWA backing, decided to eliminate the suffixes in the late '70's (with the I-35 DFW/Twin Cities splits being "grandfathered" in), the various suffixes (on I-15, the I-35 Salida branch, I-70, and I-80) were changed to what they are today.   But by that time, many cities such as Portland had rethought their commitment to freeways in general, so most of that activity went uncontested.   So what is on the ground today reflects shifting priorities over the years -- from early accommodation of various cities' wishes to rethinking and rationalizations of those decisions later down the line -- which has led to some unusual (albeit often necessary) designation choices with later system additions.

Well-done analysis! This still sometimes bleeds through; some people have said that Minneapolis is still grumbling about getting 94 and not 90.

[TEG24601]

I've noticed something in the Interstate grid. It looks like some routes ending with 4 (94, 64, 84 west) essentially act as X0 routes, serving major corridors missed by the actual X0s, often more important than the cities hit by the actual X0s. Something else happens with Interstates like X9s (29, 59, 49, 69) and X1s (81, 71, 11 in the future). Meanwhile, some X0s and X5s (30, 45) aren't exactly major regional connectors. Isn't that somewhat strange?

IMO, I-84 (West) should really be I-80.  It hugs US 30 through most of its route, as I-80 does to the East.  Of course, I would prefer if I-94 was I-90, I-90 was I-80 (connecting to I-86W across Wyoming) and going all the way to the coast, and shifting everything else up appropriately.

[Hwy 61 Revisited]

I've noticed something in the Interstate grid. It looks like some routes ending with 4 (94, 64, 84 west) essentially act as X0 routes, serving major corridors missed by the actual X0s, often more important than the cities hit by the actual X0s. Something else happens with Interstates like X9s (29, 59, 49, 69) and X1s (81, 71, 11 in the future). Meanwhile, some X0s and X5s (30, 45) aren't exactly major regional connectors. Isn't that somewhat strange?

IMO, I-84 (West) should really be I-80.  It hugs US 30 through most of its route, as I-80 does to the East.  Of course, I would prefer if I-94 was I-90, I-90 was I-80 (connecting to I-86W across Wyoming) and going all the way to the coast, and shifting everything else up appropriately.

Then 25 would overlap with your 80, then go up to your 90?