You may not see them in the big city, but if you visit a town then you might see a tractor. And there are more tractors at the farm, they are everywhere and farmers used them not only to till the land, but also to go anywhere they want to go. Sometimes, they even use it to deliver some produce they have.
In this game, you will need to deliver some farm produce to the market, wherein they will be sold to customers. You need to make sure that you deliver them in good condition. Try to deliver them as fast as you could because there is a time limit.