US-93 is a fine route number. If it had to be interstate, I-515 would also be fine.
To make another I-476? Uh, no thank you.
What aspect of I-476 are you objecting to? I assume not its bitter environmental opposition. Just that it's long for a 3di? There's lots of space between cities in the intermountain west, I don't see length by itself justifying a low traffic 2di.
Creating a 300-mile 3di just because it has low traffic? I know you want all those other corridors to become interstates, but couldn't one of them use I-13 in lieu of I-11?
I'm not advocating an interstate there at all. Let Arizona build whatever they want, but interstate route numbers should be allocated more objectively.
So, I-13 is too unlucky for Nevada and Arizona, but it would be just fine for the losers on the coast? Using number I-13 for one of the other possible interstates I mentioned would be even worse for the grid than I-11 is already.
It would make the grid neater. But of the traffic from St. George to Vegas, I bet 99% of it continues toward California.
And I bet 99% of the traffic from Memphis to Chicago has no intention of going through St. Louis. But that didn't stop them from routing I-55 through all three.
There's significant traffic from Chicago to St. Louis, which has not been demonstrated for Las Vegas-Phoenix.
The point is that the interstate system has a lot of areas where the road doesn't necessarily follow, or continue on, the way you want to go. I-94 is a better example of this.
So there are other cases of the interstate not following the traveled route. Does that mean we should create even more instances of it?
There's significant traffic from Chicago to St. Louis, which has not been demonstrated for Las Vegas-Phoenix.
It hasn't?
http://mpd.azdot.gov/data/aadt.aspCheck the 2010 and 2030 AADT columns. There are three busy spots: Hoover Dam, right next to I-40, and approaching the Phoenix end. At the moment, everywhere else is well under 10,000 AADT; even by 2030 only from I-40 to Hoover Dam and the area around Phoenix are projected to be over 10,000. Doesn't need to be an interstate.
In a previous post above, I said US-97 probably doesn't need to be interstate either, but it's closer than US-93. At least there are more than three spots with heavy traffic.
It's up to Arizona what they build, but if it were up to me I'd just reserve right of way for future construction of freeway from I-40 to Hoover Dam and build a bypass for Phoenix, and leave the rest alone.