12-28-2013, 05:15 PM
The Mauna Kea Support Services rangers have become pretty strict in the last few years about closing the road when there's snow or ice on it, so it's unlikely you'll face driving in those conditions. Plenty of people drive up there in 2WD vehicles but I wouldn't recommend it. The condition of the dirt road has become quite bad in recent years because the traffic to the summit has increased quite significantly and there have been many occasions when I've driven up there that I was thankful I was in a 4WD vehicle. The other problem some might face is that rental car insurance in many cases won't cover you up there so if you have an accident or even a break down up there you could be facing some difficulties.