Waze announced a new feature today that will allow events planners to enter in upcoming roads closures for things like sporting events and marathons. The feature will allow events coordinators to enter in their event, pick a date and time, then select the road closures and other things that might be impacted. This should help you avoid things like marathons closures or getting stuck in game day traffic.
Right now, the launch partners are limited, including the Rock 'n' Roll Marathon series and a number of sports teams, including the Atlanta Falcons and Detroit Lions. As more companies sign up, you should see more of an impact on your routing, but only time will tell how people use it. For now, you can take a glimpse at upcoming events over on the Events page.