I'm going to go ahead and make the decision here to take the alternate route. 52 down to Bellevue to D61. It will add 21 miles and 42 minutes overall to the ride, with the longest stretch being the first leg. My thinking is that most of us will be on the highway getting to the rally and going home, let's get off the highway while we're there.
Here's an updated ride map
http://www.mapquest.com/mq/5-Iw9FeqTM