Your computer sucks
Another food for thought for whoever the "trail designer" is... Something that I have seen down in Oregon (Browns camps?).. the 4x4 (or single track) trails criss-cross with a basically graded logging road. Think of the logging road switching back and forth and the "hard" trails in between the switch backs. Makes is VERY easy to extract broken rigs, keep a group of various ability wheelers together (those not up to the task take the road to the top of the obstacle and wait/watch the rest of the group), also easy for one group to go around another, slower (or broken) group without blazing new trails. I've noticed parts of Naches the same way, the trails are broken up on occasion by the main road, allowing people to move around quite easily and maximize their recreation time.
food for thought. Doesn't work in all situations, but if the terrain allows it, can have its advantages.