I don't think you've said whether this is a road used daily by cars and trucks or something used less frequently and perhaps by more trucks and equipment than cars. I don't see any gravel, just dirt. I also see it is California, so perhaps very dry most of the time, but possibly extremely wet in winter. In any case, previous posters who emphasize keeping the water from running down the road are right. Assuming somebody uses the road with some frequency, one of the cheapest tools you might want to have on hand is a shovel. Keep it in the back of your vehicle and get out and do something about water running down the road when it rains. That helps minimize the water cutting the ruts deeper. If the road is infrequently used, another ploy is to install "water bars" which are just shallow ditches cut on a slight diagonal across the road to divert water off the road. These may be reinforced on the upper side by a piece of wood, usually a 4" or so diameter round cut from a tree, but a 4X4 will do. Wouldn't do for a driveway, but it's common practice here for logging roads and such. The final thing is, once you get the road in shape, don't let it get too far out of shape, it's a lot easier to do minor repairs with whatever equipment you have than to have to do a major re-grading and ditching.
