I don't know about common city/village planning in the USA, but where I am from, farm machines can almost always go around the village using secondary and tertiary roads. They don't need to go through the center or use the ring road. In this situation using these primary roads during traffic and driving way under the speed limit isn't the best choice from a communal point of view. Besides, given the width of their machines, driving through heavy traffic is more unsafe than going by a back road.

Of course, using the back roads often also means taking the "long road", albeit just by a couple of kilometers. I understand the urge to take the shortest route, but I think people should think of others on the road too.