Isabela is a town in Puerto Rico.
West towards Aguadilla, Mayaguez Route 2
Just get to the Route 2 and you can hitchhike from any spot along the road. Xsuzann recommends hitchhiking just passing any of the many traffic lights on the road. Having a sign where are you're heading to is always huge help.
This article is missing geo information. Ideally done with a <map> tag, alternatively use this template. It could also be that the article is including a template which has missing geo information.