do you do your structured bike plans on road?

I'm looking at bike plans that say 3 min. max intensity w/ 3 min. recovery. Or 1 min. speed intervals w/ 2 min. recovery, or x # of x mins on long hills. I want to do them on trainer but then I won't ever develop bike handling skills.
Do you guys just do your best to approximate plans or do you work indoors and just go out for your long rides?

How do I do foundation rides when I am surrounded by hills? There is a 4 mile stretch of a larger road that doesn't go over 4% grade. I'd have to do multiple loops on it to avoid hills.