The road to the trailhead is driveable for a 4WD vehicle if you take it slow. The last time I was up there on 2/6/10, I ended up winching out three vehicles. I imagine this is a common scene on weekends. If you drive up there, DO NOT attempt to drive to the trailhead inside the campground. I did and got stuck on the beforementioned date. Fortunately, I was able to winch myself out. Most of the road can be driven on, but there is little or no room to turn around at the end near the restrooms. If you want to attempt it, you better have a winch or $500, which is what I believe a towing company in Divide charges to pull you out.
Also, keep in mind that weekends tend to be busy. If you can't safely back up without getting too close to the sides of the road, you have no business being up there because there are very few places that vehicles can pass side-by-side. Yes, vehicles going uphill technically have the right-of-way, but use common sense. Pay attention to areas that you see that will allow you to safely let vehicles pass and if you are closer to one, offer to back-up. Please, please do not try and drive around a stuck vehicle. Two of the three vehicles that I winched out on 2/6 was because someone thought he could do just that. Yesterday (3/3/10), a Dodge Durango must've been going too fast and slid off the road not too far from the Mennonite camp. Somehow, he was able to call some friends in Colorado Springs to come and get him, but I had to wait for half an hour.
Photos (click for slideshow):