This is a huge crowd, and it's best to collect signatures from attendees before the enter the game. Game time is 1:10 pm, so come a couple hours earlier than that to secure parking and meet up with other petitioners. When you sign up for a shift to cover this event, you'll give your phone number. Circulators will be given each other's phone numbers to coordinate rides and meet up points and where to cover. (At the end of the game, people are inebriated and it's not as good of a collecting time).
The first 2 hours prior to game time will be the best time to collect. If you can stay for the crowd coming out, that's great, but best to reach them as they arrive.
More details about Opening Day here: https://www.michigan.org/event/detroit-tigers-opening-day
2100 Woodward Ave
Detroit, MI 48201
Google map and directions