Interstate 80N

[Bickendan]

They could have solved the redundancy issue with the eastern branches of the 80 series by just using I-60 for what was I-80N. Does it really make a difference that 60 is north of 80? Not anymore as the one post mentioned:

From a motorist's standpoint, it doesn't make any difference.  Few motorists realize that we have a plan, and I don't believe that any motorists "navigate” around the country based on their knowledge of the plan.  (They generally follow the guide signs or use maps, GPS devices, or directions provided by friends.)

The number 60 will never be used because of the way they numbered the original series, so Portland could have gotten its x0 number by using that instead of chalking up a perfectly good x0.

Would've worked well, as would calling I-80 west of Salt Lake I-60 and making I-80N, I-80.

I've always felt the rule about having the same US and I numbers in the same state as stupid.

It would have worked in the context of the US 20-26-30 swap in Oregon, too.

[KEK Inc.]

Well, I-60 would have started at Echo Jct., with I-80 running up I-84.  Would I-70 retain its number under this scenario, or would I-70 run from Echo Jct. to San Francisco, with I-60 taking I-70's spot?  Or would actual Interstate 80 between I-15/70 in Salt Lake and Echo Jct. be I-x15 or I-x70?  Maybe I've said too much.

You could have I-72 from San Francisco to Echo Jct. and have I-80 go to Portland, but that would involve renumbering 8 3dis. 

Also, why can't I-82 be I-7 or I-13?  Both haven't been used yet (neither has I-11, but that's proposed for the Las Vegas-Phoenix connection).

[TheStranger]

Well, I-60 would have started at Echo Jct., with I-80 running up I-84.  Would I-70 retain its number under this scenario, or would I-70 run from Echo Jct. to San Francisco, with I-60 taking I-70's spot?  Or would actual Interstate 80 between I-15/70 in Salt Lake and Echo Jct. be I-x15 or I-x70?  Maybe I've said too much.

You could have I-72 from San Francisco to Echo Jct. and have I-80 go to Portland, but that would involve renumbering 8 3dis. 

IIRC, when I-76 took over the I-80S in Pennsylvania/Ohio/NJ, the x80 3dis all became x76.  I think the same would apply here.

I mentioned earlier that California DID propose that its stretch of I-80 be I-76 in the mid-1950s, to try to avoid duplication with US 80...

[KEK Inc.]

Well, I-60 would have started at Echo Jct., with I-80 running up I-84.  Would I-70 retain its number under this scenario, or would I-70 run from Echo Jct. to San Francisco, with I-60 taking I-70's spot?  Or would actual Interstate 80 between I-15/70 in Salt Lake and Echo Jct. be I-x15 or I-x70?  Maybe I've said too much.

You could have I-72 from San Francisco to Echo Jct. and have I-80 go to Portland, but that would involve renumbering 8 3dis. 

IIRC, when I-76 took over the I-80S in Pennsylvania/Ohio/NJ, the x80 3dis all became x76.  I think the same would apply here.

I mentioned earlier that California DID propose that its stretch of I-80 be I-76 in the mid-1950s, to try to avoid duplication with US 80...

What would I-76 be in Colorado (at the time I-80S)? 

[Revive 755]

What would I-76 be in Colorado (at the time I-80S)? 

Possibly I-72, if the renumbering of I-80S occurred before Illinois got the number for the Springfield - Chambana corridor.  If the I-80S renumbering occurred after the creation of I-72 in Illinois, I don't know for sure, but would guess either a western I-72 or I-78 - I'd lean towards the latter since the two I-78's would be separated by a much greater distance than the two I-72's.  Of course, it could have also been redesignated as a duplicate of I-74, but since I-74 was longer than either I-72 or I-78 (and to me seems like a more important route than I-72) I'd hope not.