I'm another person who is an 'authorized user' of turnarounds on limited-access freeways. Of course, I need to be in a marked vehicle with a working amber light to be legal. A fake blueprint will get you a quick trip to the back of a scout car if you get stopped in my state.It's because it dangerous as hell and people are stupid as fuck. They don't go well together.
<--- 22+ years working the highways
The thing is, you really have no idea how much faster cars are going on a freeway compared to most other surface streets. Plus, you are typically going from a gravel surface, to a ratty shoulder with lots of gravel, dust, debris, and rumble strips straight onto the hammer lane.
Did I mention that cars on freeways are going a hell of a lot faster than you might expect. Geometrics, hills, mirages, and any other assortment of visual tricks put you at a great disadvantage when you enter the freeway in a non-standard way.
