Ken,
I and my family have been there a few times in the last twenty-odd years. The big expressway 285 is a relatively recent artifact. Just to the West of the highway there used to be a frontage road that was the actual highway from the 40s. I remember standing on parts of it, seeing sections here and there of the road and painted lane lines as the desert reclaimed its own. There was a small business, a shack really, along the old road that sold place mat things touting Hernandez's place in history because of that photograph. The last time we visited and went by there we couldn't find it, and they might have taken the last of the frontage to widen 285 to what you see today. It has definitely gotten more elaborate. I have some sun-bleached silk flowers from that cemetery (from it's trash pile) in my darkroom. I always tell myself that one day I'll get a bouquet from there, auction it on ebay and donate all the money to APUG. Like bones of a saint, and an interesting experiment in sociology.
Standing on that frontage road was a good thought exercise, the wisdom of asking people to stop changing so we can keep a particular scene unchanged for (in this case) future photographers. Future tourists of any stripe. Ourselves. Admittedly, that highway lacks any grace at all but it works for them and I'm glad they have it. I do wish I had photographed that little store and its place mats though; like the place mats with the mushroom cloud that (Robert Frank? Winogrand?) took. So now my first rule is 'There's no real coming back. Get the shot'.