Random facts about interstates and US routes

[Max Rockatansky]

FYI there's an unsigned I-305 in Sacramento. Only existing per FHWA, I believe Caltrans doesn't recognize it.

Kind of with Caltrans but rather more so the  State Legislature:

https://www.gribblenation.org/2021/01/us-route-50-in-west-sacramento-and.html?m=1

[Sapphuby]

US 31W and US 31E come within three miles of each other near Cave City, KY, but never intersecting for miles.

[SkyPesos]

US 21 is an exception to the "x1 US routes are major" rule, even in its peak length. Four of its neighboring N-S routes (19, 23, 25 and 27) are longer than it, probably because 19 goes through FL, 25 goes through MI, 23 and 27 goes through both, and 21 goes through neither. I wonder how US 21 got the x1 designation then...

[MATraveler128]

US 21 is an exception to the "x1 US routes are major" rule, even in its peak length. Four of its neighboring N-S routes (19, 23, 25 and 27) are longer than it, probably because 19 goes through FL, 25 goes through MI, 23 and 27 goes through both, and 21 goes through neither. I wonder how US 21 got the x1 designation then...

That’s because US 21 used to run to Cleveland, Ohio before I-77 came along. Back then, it was a true x1 US highway. Now it ends in Wytheville, Virginia. And also, 21 is west of 19, which was done to keep the grid in order.

[SkyPesos]

US 21 is an exception to the "x1 US routes are major" rule, even in its peak length. Four of its neighboring N-S routes (19, 23, 25 and 27) are longer than it, probably because 19 goes through FL, 25 goes through MI, 23 and 27 goes through both, and 21 goes through neither. I wonder how US 21 got the x1 designation then...

That's because US 21 used to run to Cleveland, Ohio before I-77 came along. Back then, it was a true x1 US highway. Now it ends in Wytheville, Virginia. And also, 21 is west of 19, which was done to keep the grid in order.

You missed the bold part. I know that it used to go all the way north to Cleveland, it's that 19, 23, 25 and 27 are still longer even with that.

[MATraveler128]

US 21 is an exception to the "x1 US routes are major" rule, even in its peak length. Four of its neighboring N-S routes (19, 23, 25 and 27) are longer than it, probably because 19 goes through FL, 25 goes through MI, 23 and 27 goes through both, and 21 goes through neither. I wonder how US 21 got the x1 designation then...

That’s because US 21 used to run to Cleveland, Ohio before I-77 came along. Back then, it was a true x1 US highway. Now it ends in Wytheville, Virginia. And also, 21 is west of 19, which was done to keep the grid in order.

You missed the bold part. I know that it used to go all the way north to Cleveland, it's that 19, 23, 25 and 27 are still longer even with that.

Shoot, I did miss that. Maybe US 21 could have reached Florida if it were sent down US 301 in Orangeburg, SC and assumed that all the way down to Sarasota with the rest of 21 becoming a state route. 301 is rather long for a 3dus.

[Flint1979]

US 1 thru 31 are all original 1926 routes.

[Mapmikey]

US 21 is an exception to the "x1 US routes are major" rule, even in its peak length. Four of its neighboring N-S routes (19, 23, 25 and 27) are longer than it, probably because 19 goes through FL, 25 goes through MI, 23 and 27 goes through both, and 21 goes through neither. I wonder how US 21 got the x1 designation then...

That's because US 21 used to run to Cleveland, Ohio before I-77 came along. Back then, it was a true x1 US highway. Now it ends in Wytheville, Virginia. And also, 21 is west of 19, which was done to keep the grid in order.

You missed the bold part. I know that it used to go all the way north to Cleveland, it's that 19, 23, 25 and 27 are still longer even with that.

Shoot, I did miss that. Maybe US 21 could have reached Florida if it were sent down US 301 in Orangeburg, SC and assumed that all the way down to Sarasota with the rest of 21 becoming a state route. 301 is rather long for a 3dus.

Also not considered:

On the original 1925 list, US 21 ran to Jacksonville FL.

While the final list truncated that to Yemasee SC, US 21 was still longer than US 19 (Lawrenceville GA to Bluff City TN and Gauley Br WV to Erie PA), US 23 (Portsmouth OH to Mackinac City MI) and US 27 (Cincinnati to Cheboygan MI).

US 19 and US 23 were extended long disances in 1930 and US 27 surpassed US 21's length in 1934.

Incidently when US 23 was being extended south, AASHO said it had to replace US 19 south of Asheville with US 19 being rerouted to run south of Franklin NC so that US 23 would stay west of US 19.  There was so much protest from Western NC that AASHO relented and US 23 was run the way it does now in NC and GA.

[ethanhopkin14]

US-191 is an original route but has nothing in common today with it's original route.
I don't know if it's the only one, but still pretty unusual. 

[SkyPesos]

^ I've always thought I-29/I-49 as a better I-45 than actual I-45 itself.

Agreed - and then I-45 could be a better I-41 than actual I-41! 
[/fictional]

Didn't know how I skipped over this post initially, but if that is the case, that would make two 41 and 75 Interstate/Parallel US Route pairs: I-75/US 41 and I-41/US 75.

[paulthemapguy]

^ I've always thought I-29/I-49 as a better I-45 than actual I-45 itself.

Agreed - and then I-45 could be a better I-41 than actual I-41! 
[/fictional]

Didn't know how I skipped over this post initially, but if that is the case, that would make two 41 and 75 Interstate/Parallel US Route pairs: I-75/US 41 and I-41/US 75.

Just like 78 and 22!

[SkyPesos]

^ I've always thought I-29/I-49 as a better I-45 than actual I-45 itself.

Agreed - and then I-45 could be a better I-41 than actual I-41! 
[/fictional]

Didn't know how I skipped over this post initially, but if that is the case, that would make two 41 and 75 Interstate/Parallel US Route pairs: I-75/US 41 and I-41/US 75.

Just like 78 and 22!

Also 70 and 40!

[Mapmikey]

US-191 is an original route but has nothing in common today with it's original route.
I don't know if it's the only one, but still pretty unusual. 

This is also true of US 601

[CNGL-Leudimin]

Well, AFAIK US 191 has a section of its original route in West Yellowstone (and unofficially to Madison Campground), but it is now reversed (what was originally North is now South and vice-versa), and for a time it wasn't part of US 191. US 601, on the other hand, has none of its original route remaining.

[Max Rockatansky]

Well, AFAIK US 191 has a section of its original route in West Yellowstone (and unofficially to Madison Campground), but it is now reversed (what was originally North is now South and vice-versa), and for a time it wasn't part of US 191. US 601, on the other hand, has none of its original route remaining.

Even weirder, US 191 in the western part of Yellowstone National Park is actually signed:

https://www.gribblenation.org/2021/11/us-route-191-in-gallatin-range-of.html?m=1

[ethanhopkin14]

On the subject of US-191, how many 3dus are longer than their parent?  In US-191's case, comically longer that it is now a border to border highway. 

[SkyPesos]

On the subject of US-191, how many 3dus are longer than their parent?  In US-191's case, comically longer that it is now a border to border highway.

Three of the x21s (221, 321, 421) are longer than US 21. 421 is long enough that it probably could've been US 37, and 231 as US 39, but that's fictional.

[US 89]

On the subject of US-191, how many 3dus are longer than their parent?  In US-191's case, comically longer that it is now a border to border highway. 

US 278 is longer than US 78.

[JayhawkCO]

On the subject of US-191, how many 3dus are longer than their parent?  In US-191's case, comically longer that it is now a border to border highway.

US491 is also longer than US91.

[MATraveler128]

US 202 is longer than the eastern US 2.

[jlam]

US 281 is longer than US 81
US 180 is longer than US 80

[kphoger]

Someone correct me if I'm wrong, but...

US-21 – 393 miles
US-221 – 734 miles
US-321 – 526 miles
US-421 – 941 miles

US-78 – 715 miles
US-278 – 1077 miles

US-80 – 1032 miles
US-180 – 1127 miles

US-81 – 1234 miles
US-281 – 1872 miles

US-91 – 163 miles
US-191 – 1657 miles
US-491 – 198 miles

[jlam]

US 166 is longer than current US 66.
US 199 is longer than current US 99.
US 400 is longer than current US 0.


Are there any 3di that are longer than their respective 2di?

[ethanhopkin14]

US 166 is longer than current US 66.
US 199 is longer than current US 99.
US 400 is longer than current US 0.


Are there any 3di that are longer than their respective 2di?

I am praying for Interstate 297.

[JayhawkCO]

Are there any 3di that are longer than their respective 2di?

In a state, sure, but otherwise, no.