After you have started farm road 29, and go past the 3rd checkpoint, you immediately will make a hard left onto the railroad tracks. Then you can go the length of the tracks by driving on the left side of the tracks or driving on the tracks until you see the 4th checkpoint on your left.You must drive on the left side of the tracks when a train is coming because you will get stuck on the opposite side of the 4th checkpoint if you don't. If you do this correctly, you can shave as much as seven seconds off your lap time.