I'll also suggest the land plane, provided your road is in reasonable condition. I had a box blade and two different rear blades, but after getting my road in decent shape, I kept the box blade to move grave when I have more delivered, but traded both rear blades for a new Land Pride land plane. I really like it, and so do my neighbors!
The advantage of a land plane is that it works somewhat like a road grader, where the blade "floats". With a rear blade, you are often creating exaggerated undulations from the tractor rising and falling with the minor dips and mounds in the road. A land plane with two blades will fill in the low spots and cut down the high spots without a lot of work. I'm sure a pro can get similar results to the land plane using just a rear blade by running the blade backwards, but a land plane will give most of us average guys better results in less time.
Again, this is all assuming that your road is decent to begin with-if not, you'll still want a box blade or rear blade. Besides, who doesn't want more "toys"?
Finally, remember to crown the road for runoff, and be sure to have enough gravel/rock to have something besides dirt to work with.