Largest metropolitan area without an x0 or x5 Interstate

[SkyPesos]

If we're deciding which non-x0s and x5s function like one now, here's my list...

Pseudo x0s: I-94, I-64, I-84

Pseudo x5s: I-29/49, I-77, I-81, Future I-69

Not-so fun fact: A completed I-69, including I-69E into its length, would be longer than all x5s except I-75 and I-95, and it's pretty close behind I-75's length. If you include all 3 branches, it may surpass I-95's length too.

[JayhawkCO]

If we're deciding which non-x0s and x5s function like one now, here's my list...

Pseudo x0s: I-94, I-64

Pseudo x5s: I-29/49, I-77, I-81, Future I-69

Not-so fun fact: A completed I-69, including I-69E into its length, would be longer than all x5s except I-75 and I-95, and it's pretty close behind I-75's length.

I might add western I-84 to your pseudo x0s list.

[jmacswimmer]

If we're deciding which non-x0s and x5s function like one now, here's my list...

Pseudo x0s: I-94, I-64

Pseudo x5s: I-29/49, I-77, I-81, Future I-69

Not-so fun fact: A completed I-69, including I-69E into its length, would be longer than all x5s except I-75 and I-95, and it's pretty close behind I-75's length.

I might add western I-84 to your pseudo x0s list.

I might offer up I-44 as well?  I tend to think of I-44 as fill-in I-50, I-64 as fill-in I-60 (maybe it would have even been numbered such if not for US 60), and I-94 as fill-in I-100 (similar to US 101).  And the western I-84, per its original numbering, really does serve as an I-80 corridor branch towards Oregon & Washington.

[SEWIGuy]

Metro areas with populations > 1M without I-x0 or I-x5s:

40   Milwaukee-Waukesha, WI MSA   1,574,731

I-94 is not technically an x0, but it functions like one.

How does it "function" like one?  I-x0 and I-x5 function just like any other interstate.  The number just carries on longer.

[SkyPesos]

If we're deciding which non-x0s and x5s function like one now, here's my list...

Pseudo x0s: I-94, I-64

Pseudo x5s: I-29/49, I-77, I-81, Future I-69

Not-so fun fact: A completed I-69, including I-69E into its length, would be longer than all x5s except I-75 and I-95, and it's pretty close behind I-75's length.

I might add western I-84 to your pseudo x0s list.

I might offer up I-44 as well?  I tend to think of I-44 as fill-in I-50, I-64 as fill-in I-60 (maybe it would have even been numbered such if not for US 60), and I-94 as fill-in I-100 (similar to US 101).  And the western I-84, per its original numbering, really does serve as an I-80 corridor branch towards Oregon & Washington.

Added western I-84 in. Makes sense as a sort-of x0, as it used to be I-80N, and in my fictional planes, I thought it was important enough to carry the I-80 mainline west of SLC.

I-44, maybe, though it's shorter than the others by comparison, and imo I see it more taking a role like I-71 or eastern I-76, than a x0.

[Flint1979]

Metro areas with populations > 1M without I-x0 or I-x5s:

40   Milwaukee-Waukesha, WI MSA   1,574,731

I-94 is not technically an x0, but it functions like one.

Then you have I-45 that doesn't act like it should an is an intrastate serving two major Texas Metro Areas.

Yeah good point I didn't think of I-45 being so short when I saw this. I-94 indeed functions as a long haul route.

[paulthemapguy]

Hell, I-94 has more tenacity than most x0's, surviving its detour around Lake Michigan without being deemed a different designation once it turns from southeast to northeast (or SW to NW).

[mukade]

It is interesting that the consensus is that highways such as I-64, I-69, I-81, and I-94 are essentially equivalent to I-x0 and I-x5 routes (Pseudo x0s and Pseudo x5s). Strong points have been made to support these beliefs.

I believe a lot of these weird numberings were a result of rules prohibiting the same Interstate and US numbers existing in the same state. For example, because Kentucky has US 60, there never could be an I-60 route in that state. Well that is all out the window with the I-41/US 41 and I-74/US 74 concurrencies.

With that said, the AASHTO applications all start with this statement:

The U.S. Numbered System was established in 1926 and the Interstate Numbered System was established in 1956. Both have reached the period of review, revision, and consolidation. They now need perfecting rather than expansion.

Perhaps that statement should be taken seriously to address some questionable choices that really should be reviewed.

[SkyPesos]

I believe a lot of these weird numberings were a result of rules prohibiting the same Interstate and US numbers existing in the same state. For example, because Kentucky has US 60, there never could be an I-60 route in that state. Well that is all out the window with the I-41/US 41 and I-74/US 74 concurrencies.

I-70 theoretically could've been I-60, if both it and US 60 didn't run cross-state in Missouri. It's pretty much the only state both routes have significant portions in, and even then, I-70 is way north of US 60, never meeting it. I-24 was allowed in IL since day one despite US 24, I don't see why not for "I-60" either.