I noticed that after I had posted when I checked his previous posts.
I've ridden a short stretch of I-84 - east of Boise - where there is no alternative paved route.
I've also driven both interstates extensively.
I-84 is tolerable - - I-80 is really nasty - - especially on a bike.
It is a shame that cycling advocacy groups such as ACA do not press for a non-interstate solution to the TransAm section.