Andrew Crask

Carb Day Friday's final two hours of practice for the 110th Indianapolis 500 got under way as scheduled at 11:00am and looks set to run for its planned two-hour duration, although expected rain could affect the afternoon's Pit Stop Challenge, slated for 2:30pm. While just staying out of trouble is a priority for many of the contenders today, some – like Arrow McLaren's Pato O'Ward – who are shaking down a backup car after crashing their qualified cars on Monday, have a more significant checklist.

Friday's traditional Carb Day, which includes the final practice session ahead of the Indianapolis 500, has extra layers of importance this year. Beyond the decision facing Alexander Rossi and his ECR team on whether the 2016 Indy winner will be clear to take up his front row start following his heavy crash on Monday's post-qualifying practice session, it will provide a chance to learn as much as possible about a track that has had considerable rain in the interim.