The First weekend of the month is opening day at the track, when race teams start showing up. Also that day is the mini-Marathon. It starts downtown and runs around the track and then back (30 - 40 Thousand runners) the city is pretty much closed during this time, all streets blocked.
Then the first week of Practice.
Second Saturday is Pole Day, Huge turn out. Sunday continues qualifications. Both days traffic can be crippling if roads don't get closed.
Then the second week of Practice.
Third Saturday is continued qualifying followed by Bump day to complete the field. Sunday (Bump Day) is almost as buisy as Pole day as people see who the final field will be. A lot of Out of towners that arn't already here show up on this day too.
Final week of practice.
Friday is Carb Day. This is the Big party day. Concerts and you name it go's on, it's also when they lock up all the cars before the race. (All inspections are finalised on carb day and the cars are locked so NOONE can get to them) Everything is chaos, leave town.
Saturday is the Parade, folowed by parties. Roads closed Ect...(Am I sounding repetitive yet?)
Then the race. If you not going don't go NEAR the track. All lanes go one way toward the track. If you live near there you can leave via police escort or by taking special bus's. After the race all lanes go out.
The next few days as cleanup starts and people leave dumpsterg garbage trucks and suck can clog some roads.
This is only the month at the track. You could write a book about all the other events, sales, and activites that hapen at this time. the 500 really is a month long event.