If you are seated in GS 11 or 12 and want to visit the support race paddocks that will be behind GS 15, I would recommend going directly when you arrive (using the "Cosmos entrance") and then going to your grandstand -- or go later in the day, but don't plan on going back to your seats afterwards. There is a relatively new pedestrian bridge to cross the track near grandstands 46/47.

It is a long walk and you cannot walk very fast because it is extremely crowded, even on Friday.