The PACER test has 156 time periods of running mixed into 21 levels.
The first levels have fewer time periods, and the number of time periods steadily increase all the way to level 21.
I have beaten the PACER test multiple times. It is more about endurance, than raw speed. The last level is similar to running a 60-65 second 400m.
I did beat it twice on the same day. We would have one group go, while the other group kept "tick" marks of how many run periods you completed. (My partner keeping the "tick" marks ended up spraining something, and our teacher was adamant that the same number of people do both groups. Since he was my partner and I was on the track team at the time, I ended up running with both groups. The second group had a freshman wrestler that was from a dominant wrestling family, and was in great shape. I couldn't let a freshman beat all the seniors. I ended up getting to sit out of track practice for two days to recover.)
My track times at the time were 2:02, 4:56, 10:34, 16:35. (I had done a half a month later in 1:18:34.)