The I-29/I-80 thing is about separating the newly opened dual-divided freeway, which was built over the same place as the existing four-lane, so I wouldn't see it on the same level.
Speaking of, though: Should I handle that in some manner? Right now I-29 and I-80 have a concurrency. The split puts I-80 on the inner "Express" lanes and I-29 with "Local" lanes (also signed as I-80). It can be argued that if one travels I-29 through, they were never "on" I-80, and vice versa.
I can do nothing, mark the two exits in the middle as "closed" on I-80 (since, if you are traveling the Express, you can't take them), or twiddle some coordinates to break the concurrency.