So, a lot of people say that their automated tractors and trucks get lost a lot, which is a problem I never had when I set up the auto-pilot. But then I realized something:
Most people use foundations as highways. When I set up my tractor routes I usually use the "natural roads" that are on the map (ironically, the river is the best road if you are in the desert).
I noticed before that if I drive over foundations with any kind of vehicle that they sometimes behave somewhat erratically, even when I just drive straight. This is especially pronounced in the Explorer, with the wheels skipping and jumping. This mostly occurs on the borders between foundations.
I think what's happening is that, when you place down two or more foundations, even though they snap together they do not form a perfectly even surface. Vehicles will bump into these uneven bits of foundation and get knocked off of their set course.
Could someone investigate this and maybe improve the way foundations connect?