Drive south out of Santiago pass the airport, the vacant toll plaza and get off at first exit for lavega,make a right hand turn when you get off the hwy, you should have a duty free zone to your left side, then just continue on straight up up up up the mountains to Jarabacoa.
It will take probably an hour or so maybe longer because the scenery going up to Jarabacoa the first time is beautiful,You wont realize that you are in the caribean anymore, It reminds me alot of upstate NY more than most places in the DR. As for traffic it should not be that bad at anytime once your out of Santiago, except for the trucks that can barely move up the mountain.
Probably an hour, its Friday so not many trucks certainly not on this hour but a lot of people coming from Santiago and Santo Domingo to their second house in Jarabacoa.
Sunday is disaster day because a lot of locals drive up towards La Confluenzia and you don't want to be stuck at the end of a long, long trail of "cars" who barely can climb :bunny:
Add another 15 minutes from Jarabacoa city to the River Club.
Give a sign when you arrive, love to meet you!