The Tractor Mission is similar to the Lawn Mowing mission. It is located at CrazyBob's Farm, it can be done in any city but tractors only spawn in SF. It can be started by going in the checkpoint with a tractor near the farm. Once it's started, you have a limited amount of time to reach as many checkpoints as you can.
Upon completion, you get a small bonus and if you can get the most, you will set a record.
To start this mission, go to CrazyBob's Farm and approach the checkpoint near the two tractors. Type /mis or /mission in the checkpoint, it should begin the mission. You need to be in a Tractor to start this mission.
You now have 2 in-game hours to get as many checkpoints as you can.
Type /cancel during a mission at any time to cancel it. Once cancelled, you will have to wait several minutes before starting it again.