It's a little hard to say, b/c it's not a holiday weekend and w/ the exception of 1 other time, all the past race weekends have been on 3 day weekends. But if I remember that 1 time, I didn't have a problem w/ huge crowds and was able to get a lot done that weekend. It won't be crazy like summer or X-mas, but there will be more people that weekend than were there not a race. The crowds will pick up on Fri when most of the runners will start to come in. Some might Thursday, but not enough to really notice.
Saturday is the 5k, but that is early in the morning and should be completely clear by the time the park opens. Saturday night will be better than the morning/afternoon, b/c a lot of the runners will be back at the room resting. Restaurants Fri & Sat that are more carb-based like Wine Country in DCA or Naples in DTD will be packed both nights, so if you'd like to eat there those days, try to make sure you get a reservation beforehand.
Sunday, the race starts at 5:30 and people will be out there until 9:30/10 so there will be congestion on the roads from early, early morning to 10-11. The course hasn't been published yet so it's hard to say what to avoid. The start and finish for the other races are along
Disneyland Dr by the resort hotels. The parks will be open and the runners cleared by the time it's open to the public. In the past we've run through DTD so you might encounter runners there. We've also run down Disney Drive into the back parking lot behind DCA. If you're staying closer to Katella, you might have to cross the course Sun morning, but they'll have people helping so it's not too bad. Just leave a little earlier than normal if you want to be in the parks for rope drop. Nice thing park wise is that the morning in the parks will be a little quieter, b/c people are finishing up their runs and back in the room showering and eating. Most runners that go to the park go late morning/early afternoon. And b/c of all the road closures, HB probably wouldn't be best Sun unless you don't have a problem leaving until 10-11 in the morning after roads open up.
Hope that helps!
