Consider how a muddy road forms. If a path is ridden often, the topcover will erode away, leaving open soil. Add some water and you get mud.

So there are several possible answers;

• Make alternate routes so that a road that has eroded badly can be left alone for a while and has time to recover.
• Add an erosion-resistant cover to the road, preferably from locally available materials
• Improve the drainage.
• A combination of one or more of the above.

If you have both clay and wood available, you could e.g. make bricks to cover the tracks.

Yeah, yeah. We know those are the long term solutions, but barring a month and a few thousand dollars to work on the driveway, we tend to just work with the weather and try to drive when the ground is frozen or dry.

Mark's been wearing away at me and stealing a few days a year to pour gravel into the driveway, so I figure in a decade or so, he'll have fixed it all up.