I don't see the point of this when you have a system in place with the information. With off-road you don't necessarily have registration to work from.
What system are you referring to? DMV doesn't track usage, frequency, mileage, location, fuel use, etc. - at least not to the extent that these surveys capture. Inventories supplemented by data from these surveys are the systems in place to model a number of parameters from various sources and are used for a multitude of purposes. You can even access some of the data publicly. I posted the link in the other thread.