Here's the problem: Songtaews are only permitted to travel from a beach to Phuket Town (not from beach to beach). Tuk-tuk drivers have exclusive rights to transport people between beaches, so the "service" is run as a racket -- pay the fare they demand, or walk. At night, tuk-tuk drivers are known to charge solo passengers up to 1,000B to go from Karon to Patong Beach, but they are the only game in town. Budget travelers on limited funds must bear this in mind to avoid getting stranded late at night. If you plan to stay several days and want to explore the island, renting a car is the obvious answer.
Read more: http://www.frommers.com/destinations/phuket/640800#ixzz3lgiZYWfz