The intelligent traffic system has two kinds of user interfaces, a website and a GPS. I conducted a survey at the department of land transportation in Bangkok. I randomly selected a texi driver to be a participant. The survey revealed user requirements and verified some business ideas. I also conducted unstructured interviews with the taxi drivers to understand their experience and problems. I would like to solve that problem that a normal GPS is hard to use when a driver is driving a car. I purposed speech recognition to control GPS because a driver must not abandon the wheel. I drew a low fidelity prototype according to the survey data.