Intelligent Transportation Systems

Intelligent Transportation Systems

Intelligent Transportation Systems (ITS), advanced electronics, communications, and computer systems that increase the efficiency and safety of highway transportation. Originally known as Intelligent Vehicle/Highway Systems (IVHS), these technologies can provide real-time information exchange between drivers and the roads, giving rise to the terms smart cars and smart highways. As the technologies have expanded to include public transportation and commercial vehicles, this range of technologies has become known as the Intelligent Transportation System. Increasingly, drivers will have access to up-to-the-minute information on traffic conditions, alternate routes, and directions to unfamiliar destinations. Ultimately, vehicle control may be automated.

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TRAFFIC CONTROL

Electronics and computer systems are currently used in advanced traffic management to improve traffic control. Traffic along major highways in some cities is monitored by remote cameras, radar, or sensors in the roadway. A central computer system analyzes the information. If roads are congested, traffic flow can be improved by automatically adjusting traffic-signal timing, controlling traffic flow on freeway ramps, or providing information to drivers by means of electronic signs along the roads.

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TRAVELER INFORMATION

Advanced traveler-information systems are currently available in some new automobiles. These are navigational systems into which drivers enter their destination. An electronic map then displays the best route on a small screen, or a synthesized voice provides directions along the route, including directions on when to turn. These systems use a transponder, or a transmitting and receiving device, in the vehicle and a satellite-based global positioning system to pinpoint the exact location of the vehicle along its route. When this navigation system is coupled with cellular-radio technology, it can be used to signal a central dispatcher in case of an emergency.

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VEHICLE CONTROL

Automated vehicle-control technologies are currently under development to improve highway safety. These devices are aboard the vehicle and can alert a driver to an impending danger or, in an emergency, can override the actions of the driver. A radar system has been adapted for use in school buses that detects the presence of a person near the vehicle and then warns the driver. Radar and sensors are also used to detect another vehicle in the driver's blind spot—that is, in a position that is not visible in the mirrors. Infrared sensing and other methods of visual enhancement to improve safety during night driving or during adverse weather conditions such as fog, snow, or heavy rain are also under research. The most ambitious ITS project is the automated highway, on which vehicles can travel at high speeds and at close intervals by means of on-board radar, vehicle-position and engine sensors, actuators for acceleration and braking, and computer links between vehicles.

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COMMERCIAL USE

Commercial vehicles, trucks, and buses also use ITS technologies. Transponders allow these vehicles to pay tolls, obtain permits, and accomplish other routine functions while in motion, saving the time and expense of stopping. Electronic toll collection for passenger cars is also currently available in some metropolitan areas. In the future, commercial shipping companies will be able to track specific vehicles and eliminate weigh stations by using weigh-in-motion systems.

ITS technologies are expected to improve the efficiency of intermodal transportation, the use of a combination of modes of transportation, such as automobiles, mass transit, and airplanes. Commuters will be able to receive information on the location of bus, train, or subway stations, parking availability, and current arrival and departure times. The availability of advanced information is expected to increase the use of mass transit and thereby decrease traffic congestion.