From Samana/Nagua/Santo Domingo crossroad it's about 1 hour 30 to 45 minutes easy drive. There is a portion of about 15 kms of many MANY blind curves uphill and downhill where you cannot go fast, and if you "meet" some truck in your lane... better pull over and have a fria...(agua fria, that is). You will end up at SD airport. From there, it's 40 minutes to San Pedro, 30 minutes to La Romana, 50 minutes to Higuey, 45 minutes to 1 hour to Bavaro, plus 20-30 minutes for SP/LRM/HY crossing. Total: 4 hour 45 minutes (minimum) to 5.5 hours, not including rest-stops. Plus time from Sosua to Samana highway.