As Hariette said the road is good as far as Grand Caribe after that it is really bad.
Best bet is to hire a bike from Joe's and just cycle on the beach as far as you like..I will probably be out our on my balcony at Grand Caribe drinking a Belikin so I'll give you a wave as you pass by!
Since we moved up to Grand Caribe we find it much quicker and enjoyable going by bike into town rather than a golf cart and really wouldn't go further north on a golf cart.

Colin, Marianne & Sophie the Dog
www.mrptny.com