There is another fairly recent thread here somewhere about this stretch of highway. It's a very easy drive - much smoother, less curvy and safer than the Hana Highway, IMO. It also cuts a considerable amount of time off of your drive. If you're approaching it from Oheo Gulch, the ranger station there does have a board up telling you current conditions. If there has been recent heavy rains, I believe it can make the very first part (which is well-graded gravel) difficult for 2WDs, but I did it earlier this year in a 2WD about four days after heavy rains and it was quite easy and pleasant. If you're approaching from the other direction and you have any question, you could give the folks at the ranger station a call first.