Missed many many many roadside landscapes... From the Great Flatness of Nebraska (i.e. hte Platte River valley along I-80), to the scenic vistas along and approaching the Front Range, to the tight, intimate (relatively speaking) views in the winding little highways climbing up thru the canyons to hte High Country... I've seen so many shots and missed 'em because I couldn't get off the road (traffic, no parking, cliff, etc...)
And, of course, I have had some (many) shots with bad settings (forgot to change ISO from 800, that sort of thing) too.
Jim