Actually, on the Alvord playa the tire tracks will be gone after next winter/spring when the playa is covered with water -- as it was when I was in the area in December, covered with water even though it was a low-precip winter out there:
Sure enough, when I drove out there this week there were few tracks visible even at the main access point -- and none in the vicinity of where I camped -- even though during the previous dry season dozens (at least) hundreds (possibly) had driven through the area I camped.
In any case, the Alvord Playa is dead-sterile -- nothing lives on or in it, and it's flat so erosion is not an issue, either. Tire tracks are not an environmental issue at all -- just an issue for human aesthetics. The birds and bees (the only creatures I've ever seen out there) don't mind tracks at all. Even still, any aesthetic "damage" is transitory -- in this case lasts not more than a year.
Seems like for the most part MBC is right. Tracks from vehicle travel seem to be very transitory on the playa surface. Maybe only issue in these changing times is a fully flooded playa seems to be a rare occurrence as we see wet winters with lots of snow melt not so often these days. "My" biggest concern with vehicle access on the playa is it enables "not thinking or incapable of thought" humans ready access with all sorts of off highway vehicles to the extremely fragile areas surrounding the playa, delicate stabilized dune and greaswood plant and animal communities. So, maybe in my perfect world we would have to do all our travel via our feet out there but I for one sure enjoy being able to truck camp "out there" in the big space. My $.02...
I've been to this area many times. I've seen vehicles of all sorts, including sail powered carts. It's very wet in the winter and hard as a rock in the summer. The wind blows so hard here at times it will erase anything. We used to drive out there at night and drive as fast as we could. A lot of fun. I need to make it down there again sometime soon.