Most of the road is paved but sections are normally under construction during the summer months.  Most of the paved sections are oil and chip. Which consists of liquid tar or asphalt  sprayed on a dirt road bed. Loose gravel chips  are spread on top.  Travel on these sections is dusty with lots of flying chips which are tossed in the air by vehicles coming from the other direction.  Windshields are a big target.  Frost heaves are also present which can make for a bumpy ride in spots.  Road conditions change daily.  You never know what might be around the next corner or crest of the hill. Dry days bring dust, rain brings the mud.  I have seen almost every type of vehicle driven on this road. Each year the road improves.  The view is spectacular and worth the trip.