Easiest & quickest way - drive yourself
it takes about 2 hours depending upon traffic.
Cabarete to Sosua - 10 min along the coast
Sosua to Puerto Plata - 10 mins follow the same road
PP - Navarette - 40 mins, ride through PP on the high side, thunder through the mountains early in the morning, look for the sign Santiago at the Nvarette crossing
Naverette - La Vega - 35 mins, depending on traffic in Santiago, make sure you take the right side on the overpass out of Santiago (look for a sign on your left with Santo Domingo, once you pass the 2nd La Sirena)
La Vega - Jarabacoa - 20 mins take the first turnoff from La Vega and take a right at the lights by the Texaco station... it's not signed but that is the start of the mountain road up to Jarabaco