You could spread 4-6" of black dirt. Easy enough to write the check and have the same dude do it whenever he can get to it. If you didn't want to go that route, you could also just unroll some round bales on that road. You'll get plenty of grass seed from the hay, and it'll cover the sand long enough that it should take hold. Then just mow it once a year, or as you see undesirables filling in. I bet you could cover that whole road with 4-6 round bales. Just cut the twine and start pushing with the tractor.
Might not be a bad idea to do a soil test on that road. You really only need a pH reading on it. You know it's sandy, but if you need some lime, dolomitic would be a good opportunity to add some magnesium.