They are graphics used in Europe for "freeway exit" and "intersecting freeways". I noticed on other occations also that they're using European/German graphics. In particular, some freeways show the number of the freeway in a yellow frame -- that's how highways are marked in Germany
Thank you thats makes perfect sense now you have explained, just wish TMC was working on this road i sat there today for 2 hours as they closed the road due to a big pile up.
now you know why Chris Rea wrote road to hell about this road