When ever you see bee boxes on the side of the road write the phone number down (it should be printed on the side of the box) and give the beekeeper a call. They are usually happy to sell their honey by the pail or barrel if you are inclined.
Hey there lucklogger, guess I am unlucky because I have never seen bee boxes on the side of the road. Maybe its just my part of the country. We barely have any apiaries in the area.