I went a year ago, and it is quite rough, especially the descent on the southern side, on the northern side the road goes through a creek bed for a while, so the rains might have damaged it quite a lot I guess.
There is another road, which is actually closed by a gate if you start in the south (it starts at the end of the large asfalted road done by the americans which leads to cabo rojo and then goes up to the moutains to the baoxide mines - this is the best road in DR, the rouhg road starts just before you arrive to ranger station). In the north it starts at Puerto Escondido, it does following the border, it is more eaterly then the road which closely follows the border. I travelled it for about 10 km from puerto Escondido, but it was too risky just for one car to travell on (the road was not used for a long time by car and was overground by shrubs a lot), so I turned back and took the more westernly track road.