@GordoJay i agree Denver is the absolute worst but I-70 is a gorgeous stretch of highway from golden to grand junction.
It is the prettiest interstate in Colorado, maybe anywhere, and the scenery is pretty good. Glenwood Canyon was the last stretch of the interstate highway system to be completed. That's because it's in a pretty place. The two-lane highways in Colorado are even nicer. If I were driving from Flag to Denver, I wouldn't go out of my way to drive I-70. The traffic between Denver and Summit County is generally horrible, for starters, and when you add in the recent fires and closures/slowdowns farther west, it could be bad. I'll be going west through there on Wednesday and back east again on Monday or Tuesday. I'm not looking forward to it, but I'm meeting family in Grand Junction. It's my least favorite road to drive in the whole state, I-25 in second place, but last time I went through Breckenridge to Frisco, that was just as bad. Too many people, many either lost, looking at scenery, or terrified, mixed in with locals in a hurry. You've got to be constantly on your toes and it's tiring. Depending on where we end up going in Eastern Utah, I may come back on 46/90/145/62/550/50/115. That's what we did on Wednesday with 491/141 in place of 46/90. That's a prettier drive and much more relaxing.