They encourage biking to the State Fair--which is big around here--at which they provide, with the help of our local cycling association, free and secure bike parking. The Fairgrounds are located just off the main MUT, so it's pretty feasible.
I haven't seen it encouraged for a lot of other events. Skhill mentioned Fourth of July festivities. In Indy, the big event happens after dusk in downtown Indy, so I don't know how feasible it is for the average person to cycle downtown. That's true for a lot of our big events that happen at night and/or in the winter--when cycling for the average person just isn't as safe or feasible.
One of our "big" daytime events is the Indy 500. Frankly, I think you have to worry about this whether in a bike or in a car, but there's a lot of drinking at the race. I'm not sure how comfortable I'd feel on a bike after the race.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher