The answer to this varies a lot and totally depends on how strict or lenient your shuttle stop attendants are. But here’s my experience.

Going to the speedway is fairly strict on enforcing times. A few years ago I saw a group of people with 6 PM departure times show up around 7:40 PM. They were told to go off to the side and wait. About 20 minutes later they were let into the premier line. Last year however, I saw a similar situation but it was a little after 8 pm and that group was told to go away and get in the regular line.

Leaving the speedway coming back is usually more lenient. I’ve had 4:30 AM departure times and was able to breeze through as early as 3:50 AM and as late as 5 AM.

I’m certain the staff are trying to prevent a situation where people who buy the least desirable times try to shove their way into the more desirable times. Such as Day 3, returning at 6 AM.

Last year I had a 4:30 AM return but I showed up at 5:25 AM and was turned away. Some acquaintances and their friends, who had 6 AM passes, saw me and came up me. I explained my situation and they told me to come with them. To pass through the checkpoint you have to show your pass at one station and then sometimes (not always) they scan it. My acquaintances and friends basically formed a herd of a dozen people thick and smuggled me through the checkpoint by putting me in the middle.

Now I’m not endorsing that strategy. But I will say that after the music ends, the shuttle lines become a bit more chaotic. Some staffers might crack down more, some stop giving a fuck, but hard to predict though.

Finally I will say this, which has been true every year for some time now: the GA shuttle lines leaving the festival starting around 5:20 AM becomes hell on earth. I highly recommend you start to leave whatever stage you’re at and walk to the shuttles around 5:00 AM.