With the probability to develop road safety and grant economic benefits, intelligent vehicles have evoked a symbolic amount of interest from both academics and industry. A respectable vehicle detection and tracking system is one of the key modules for intelligent vehicles to perceive the surrounding environment. In this paper, we considered the features of different sensors to detect vehicles for having safe vehicular traffic across the expressway. A real-time monitoring has become a vital need for the today's intelligent traffic monitoring systems (ITS). Vehicle detection systems are widely used in practice for various purposes, e.g. monitoring traffic, improving the efficiency of traffic control systems, enhancing safety, or detecting intrusion to protected areas. Existing vehicle detector systems utilize several sensory technologies, the most popular ones being inductive loop detectors, pneumatic road tubes, weight-in-motion system, microwave radars, ultrasonic sensors and video image processors.