Actually it has some logic.
The only North-South interstates between CA and NE is I5 and I25.
I5 goes thru every major city on the West Coast except San Francisco.
I25 goes right thru Denver.
That’s it.
Shipping anything north or south is real problem.
Just turn AZ 95 into the new Interstate. It already runs from San Luis AZ to Nevada. All you have to do is widen it. The only Interstate serving SW AZ is I-8. A North/South interstate through Yuma would help the economies of Yuma County, La Paz County, and Mojave County immensely. We could get rid of the excuse our politicians constantly use to explain why they don’t attempt to attract any business that isn’t a restaurant or retail.