I know about this too
@Pulsegleaner ! There is a section of winding highway just out of town that's against a mountainside; it's an OCEAN of purple blue lupine flowers in early summer. It's the only place I know of that has them, I suspect they are escapees from someone's garden that somehow managed to naturalize because they are not wild here. I've wanted to get some seed from there for years but that section of highway has no area to pull off plus it's on a curve and everyone speeds. So I always drive past and dream!
Sounds like me and a few of the crabapple trees. Over the last few years, I have been on a sort of quest to try and gain access to, and taste, the fruit of every apple and crabapple tree I see (part of is a precaution, in case the world goes kerflooey and I need to forage, It'll help to know which trees are WORTH foraging from) that has fruit bigger than a pea (below that size, I assume there isn't going to be enough apple flesh to bother). A couple are in pretty easy to get to spots (like parking lots), so they are no problem, apart from finding some excuse to be near them (like the two in the mall in Nanuet across the river which actually make full size fruit that are edible, if a little tart. Before, it was easy to have an excuse to go there, since it was right in front of the Nanuet Casual Male XL where I would go clothes shopping. But the store has since closed, so there is no longer a good excuse I can come up with to go over there to my Dad.)
But there are at least three I have yet to sample because their spots are currently totally inaccessible. There's the one in the cow field at Stone Barns (the Rockefeller farmland). The cows are all gone now (sold) but there is still the matter of the sheep, which also sometimes graze there, and whatever farmhands may be wandering around (if I can't get them to listen to me about doing something about the mass of kudzu on the gate on the other side before it causes everyone a nightmare, I don't have a hope of explaining to them why I am wandering across their field. Maybe when and if I get employed there, things will be different.)
The second is one producing cherry sized red crabapples that is in a knot of brush on the road that runs through Ardsley-On-Hudson. There, not only is there no shoulder, but it's right in front of a major turnoff; on the wrong side of course. Plus I'm not totally sure it's still there, I don't recall seeing any fruit last summer/fall.
Number three is probably in Scarsdale or Hartsdale (when you are going by roads rather than downtowns, it is sometimes hard to tell where one village ends and the next one begins) across the street from the burnt out nursery. Cherry sized fruit again, but yellow this time. There, the problem in addition to the lack of a shoulder is a blind turn with a warning light right by it to keep people from crashing into each other (not a traffic light, a light to tell you what the actual traffic light, which you can't see from there, is so you don't wind up driving head on into another car going the opposite direction. It has something to do with a long term road repair project.)
There MAY also be one in the gully at the very end of the road between Tarrytown and Pleasantville, but it's a bit too deep to see clearly (there was a REAL apple tree on the other side once, near the horse stables, but that seems to have been removed since.) That area DOES have a shoulder, but I am reluctant to try and go down there until I can visually confirm there is something down there worth going down FOR (there are a lot of nosy highway cops at that intersection, and after the incident last year with the Korean Dogwoods, I don't want to stop until I am SURE those are apples. For sort of the same reason, I haven't tried any of the ones between Tarrytown and Millwood; as I have never seen the fruit (just the flowers) I assume they are all tiny green ones.)