ITS (Intelligent Transportation Systems) technology is playing a major role in modern transportation construction by enhancing the reliability and safety of highway and city transportation infrastructure. In general, ITS involves integrating communication, control, and electronics technologies, and is used to monitor and manage traffic flow, reduce congestion, provide alternative routes to travelers, and enhance productivity to save time, money, and lives.

Roadway systems are made up of many subsystems, including Traffic Signal Control Systems, Traffic Information Display Systems, Real-time Video Surveillance and Analysis Systems, Electronic Toll Collection, Advanced Parking Systems, Automatic Vehicle Identification, and Power Substation Systems. ATMS (Advanced Traffic Management Systems) and ATIS (Advanced Traffic Information Systems) are two of the most important aspects of ITS, and as such much of the cost for ITS implementations goes into ATMS and ATIS. By using intelligent embedded traffic controllers, traffic signals, vehicle detectors, LED display boards, and traffic surveillance cameras, a road group with several adjacent intersections can work together as one coordinated system.

	Vehicle detectors collect traffic flow information, including volume, speed, occupancy, and then send the information to an intelligent embedded computer over a wireless transmission system.
	The embedded computer, which acts as a traffic controller, calculates and analyzes the data to determine the state of traffic flow, and then makes control decisions, such as when to change a particular traffic signal from red to green to avoid serious traffic jams.
	The controller sends estimated travel time information and suggested alternative routes to the CMS (Changeable Message System) display board to alert drivers of the current traffic conditions.

A major concern is system reliability. Due to the importance of traffic control, the roadway system cannot be allowed to fail due to power interruptions or disconnected transmission lines. Furthermore, since the traffic situation changes from day to day, and car accidents occur unpredictably, an additional traffic monitor/surveillance mechanism should be set up for emergency prevention and response.

A roadway system designed with a solid and reliable networking infrastructure and perfect traffic control/display strategy can help to ensure higher performance. The following items are necessary to create the ideal roadway system:

	Redundant Gigabit Ethernet Network: All roadway subsystems are connected to control center through a reliable, high-bandwidth Gigabit Ethernet network transferring large volumes of traffic data, video, and voice transmission over one IP network to allow real-time, continuous traffic monitoring and response.
	Fiber Connections: Due to the wide coverage of the traffic system, multiple fiber connections are the best solution to achieve long distance data transmission.
	Wireless Network: Traffic controllers at each intersection in the road group can synchronize collected information by using wireless networking to transmit at least some portion of the signal over either a wireless or wired network, helping save on the cost of cabling.
	Embedded Computing: The embedded computer calculates control signals in real-time to make the right traffic management decisions.
	Real-time Surveillance and Capture: Video surveillance must be available to provide real-time pictures of actual traffic conditions.
	Devices with Rugged Industrial Design: Redundant power inputs for uninterrupted system performance. Ability to operate in and withstand the extreme temperature conditions of outdoor environments, such as from -40 to 75°C. Compact size is ideal for deployment in the limited space of roadside cabinets.