and most of 580 in its original incarnation. It connected the MacArthur Maze to downtown Oakland and then headed out at Hayward past Dublin and CA-21 (now I-680) well into the sticks across Altamont Pass.
I don't know how big Dublin was in the 50s - if it counted as a major city then about half of I-580 was rural, but otherwise (if Hayward was the last population center), then over 80% of it was.
580 probably could be a 2di, at least the portion east of I-80.
The explanation from USDOT was pretty sensible. A couple comments on I-82:
- Oregon probably wouldn't have objected to a renumbering of I-82 back in 1980, as they didn't build their section until the late '80's
- I don't think I-82 should be a 3di. My problem with the number was that it should have been odd
, since the route trends more N-S than E-W. Had that thinking prevailed when I-82 was first proposed as an interstate, then the number 82 would've been available when I-80N was redesignated. But what's done is done; it would be wasteful to renumber now.
As for I-86:
- Calling this freeway I-15W was goofy in the first place, as it wasn't a N-S freeway.
- I'm less than impressed with the argument for why this is a 2di. There are some rural 3di's back east, so this isn't an absolute barrier to this being a 3di. Of course, our USDOT official could bring up the lack of available numbers in the east as a justification, and that would be a good argument. The main reason 86 is there is because Idaho wanted a 2di for that route, and weighing the 2di vs. 3di arguments I have to say the 2di status makes a little more sense.
Anyone ever consider that maybe I-84 should've been I-80, and I-80 west of Echo could've been something else? Quite a few numbers would've been available, quite a few scenarios could've been reality.