An estimated 20-50 million people get injured and at least 1.2 million people die in automotive accidents every year. To avoid this, several security systems such as lane departure warning system, vehicle detection system, advanced cruise control system, etc., have been developed. But they are very expensive. In our research, we focus on developing low cost intelligent vehicle systems. In this paper, we propose a driver assistant system based on monocular camera. The proposed system consists of two parts. First part is vehicle detection module based on adaptive boosting using extent modified census transform (EMCT). Second part is lane detection module using RANdom Sample Consensus (RANSAC). Experimental results of system shows that both modules perform robustly with less computational load and that it can be a reliable intelligent vehicle system.