Racing AI by Daedalus

First, make the track. Use white concrete for track itself, and red concrete as walls. The track has to be 1-3 blocks wide, and the walls can be any thickness. The corners shouldnt have any smoothing, only 90 degree angles like in the picture.

Then place the turtle, open it, and place a coal block in the first slot. It'll run once it's fueled.

You can place multiple on one track, but if they hit each other they might get stuck, so it's not advised. It can be fun sometimes to place a few turtles next to each other and see what happens though!