I used to drive through on a bike at the Oak Ridge, TN McDonalds all the time when I worked out there. Just grab the bag and go back to my office. No problem riding holding a bag. I don't have an easy way to test this now. Don't ride in cities. I suppose McDonald's outlets are free to make their own decisions on who to serve so long as some kind of non-discriminatory effect happens. Not serving all asians wouldn't go well, but not serving walk ups looks OK.