Here's what the Kennicott Lodge website says about the McCarthy Road:
The last 60 miles of road before you reach Kennicott (between Chitina and McCarthy) is a State maintained gravel road, passable by any passenger car, that follows the path of the historic Copper River and Northwestern Railroad. The State did extensive work on the road during the summer of 2012 and it is now in better shape than ever before. Here are a couple of tips for driving on the road.
It usually takes 2 - 2 ½ hours to drive the McCarthy Road.
The speed limit for the McCarthy Road is 35mph. If you stay under the speed limit, the risk of a flat tire or car damage is minimal.
The road is wide enough for two lanes in most places and the State has brushed most of the road to increase visibility. However, the road is still narrow in some places, so you should to watch out for other traffic.
The number of flat tires on the McCarthy road has decreased drastically in the last few years, but it is still a good idea to carry a good spare tire. There is a tire repair shop at the end of the road during the summer months if you do have a problem.