I have a different experience. I cannot imagine yours or where you may have learned it. Where is right turning forbidden without the presence of sign that allows it?
Also it is unfathomable that you contemplate merging into a highway as a "right turn." Are there no interstates with on ramps in your area??
I apologize for my OCD. In some ways this is the most disturbing meme ever for me. That is how OCD can alter interactions about rather minor details such as the semiotics of road signs.
