Modeling and control strategies for an autonomous three wheeled mobile robot with front wheel steer and front wheel drive have been presented in this paper. Although, three-wheeled vehicles with front wheel steer are commonly used automotives in public transport (especially in Asian countries), the advantages of such a design in navigation and localization of autonomous vehicles are seldom utilized. We present the system model for velocity control and autonomous trajectory control for such a robotic vehicle. Using the obtained model, the velocity control system has been designed in a digital control framework. We propose a novel trajectory control approach for accurate path following to work with the conventional motion planning high level control algorithm. The derived system model and the controllers have been validated using experimental results obtained for the robot vehicle design. Controller performance and robustness issues have also been discussed briefly.