Intelligent transportation system
Intelligent transportation system
Worldwide Initiative to Add Communications Technology
Intelligent transportation Systems vary in technologies applied, from basic management systems such as car navigation, traffic light control systems, container management systems, variable message signs or speed cameras to monitoring applications such as security CCTV systems, and then to more advanced applications which integrate live data and feedback from a number of other sources, such as weather information, bridge de-icing systems, and the like. Additionally, predictive techniques are being developed, to allow advanced modeling and comparison with historical baseline data. Some of the constituent technologies typically implemented in ITS are described in the following sections.
The ITS sector was known as Intelligent Vehicle Highway Systems (IVHS). At the time it was recognized that all forms of transport could benefit from the application of information and communications technologies (lCT). However the term ICT had not yet been described in popular vernacular. The global leaders in ITS at the time then determined that there needed to be a term to describe the application of ICT to transport and coined the term Intelligent Transportation Systems.
Various forms of wireless communications technologies have been proposed for intelligent transportation systems. Short-range communications (less then 500 yards) can be accomplished using IEEE 802.11 protocols or the Dedicated Short Range Communications standard being promoted by the Intelligent Transportation Society of America and the United States Department of Transportation. Theoretically the range of these protocols can be extended using Mobile ad-hoc networks or Mesh networking.
Longer range communications has been proposed using infrastructure networks such as WiMAX (IEEE 802.16), Global System for Mobile Communications (GSM) or 3G. Long-range communications using these methods is well established, but unlike the short-range protocols these methods require extensive and very expensive infrastructure deployment. There is lack of consensus as to what business model should support this infrastructure.
Floating car data; floating cellular data (FCD)
Virtually all motorists travel with a mobile phone in their vehicles. These mobile phones routinely transmit their location information to the network-even when no voice connection is established. These cellular phones in cars are used as anonymous traffic probes. As the car moves, so does the signal of the mobile phone. By measuring and analyzing triangulation network data-in an anonymized format-the data is converted into accurate traffic flaw information. The more congestion, the more cars, the more phones and thus mare probes. In metropolitan areas the distance between antennas is shorter and, thus, accuracy increases. No infrastructure need be built along the road-only the mobile phone network is leveraged. The FCD technology provides great advantages over existing methods of traffic measurement:—much less expensive than sensors or cameras-more coverage: all locations and streets-faster to set up (no work zones) and less maintenance-works in all weather conditions, including heavy rain
Sensing technologies
State-of-the-art sensor technologies have greatly enhanced the technical capabilities and safety benefits awaiting intelligent transportation systems around the world. Sensing systems for ITS can be either infrastructure based or vehicle based systems, or both-see, for example, Intelligent vehicle technologies. Infrastructure sensors are devices that are installed or embedded on the road, or surrounding the road (buildings, posts, and signs for example). These sensing technologies may be installed during preventive road construction maintenance or by sensor injection machinery for rapid deployment of road in-ground sensors. While vehicle sensors are those devices installed on the road or in the vehicle, new technology development has also enabled cellular phones to become anonymous traffic probes, such as floating car data.
Inductive loop detection
Inductive loops can be placed in a roadbed to detect vehicles as they pass over the loop by measuring the vehicle's magnetic field. The simplest detectors simply count the number of vehicles during a unit of time (typically 60 seconds in the United States) that pass over the loop, while more sophisticated sensors estimate the speed, length and weight of vehicles and the distance between them. Loops can be placed in a single lane or across multiple lanes, and they work with very slow or stopped vehicles as well as vehicles moving at high-speed.
Video vehicle detection
Traffic flow measurement using video cameras is another form of vehicle detection. Since video detection systems do not involve installing any components directly into the road surface or roadbed, this type of system is known as a "non-intrusive" method of traffic detection. Video from black-and-white or color cameras is fed into processors that analyze the changing characteristics of the video image as vehicles pass. The cameras are typically mounted on poles or structures above or adjacent to the roadway. Most video detection systems require some initial configuration to "teach" the processor the baseline background image. This usually involves inputting known measurements such as the distance between lane lines or the height of the camera above the roadway. A single video detection processor can detect traffic simultaneously from four to eight cameras, depending on the brand and model. The typical output from a video detection system is lane-by-lane vehicle speeds, counts and lane occupancy readings. Some systems provide additional outputs including gap, headway, stopped-vehicle detection and wrong-way vehicle alarms.
Electronic toll collection
Electronic toll collection (ETC) makes it possible for vehicles to drive through toll gates at traffic speed, reducing congestion at toll plazas and automating toll collection. Originally ETC systems were used to automate toll collection, but more recent innovations have used ETC to enforce cordon zones in city centers and ETC Lanes.
Until recent years most ETC systems were based on using radio devices in vehicles that would use proprietary protocols to identify a vehicle as it passed under a gantry over the roadway. More recently there has been a move to standardize ETC protocols around the Dedicated Short Range Communications protocol that has been promoted for vehicle safety by the Intelligent Transportation Society of America, ERTICO and ITS Japan.
Whilst communication frequencies and standards do differ around the world there has been a broad push toward vehicle infrastructure integration (VII) around the 5.9 GHz frequency
(802.11 .x WAVE)
ITS Australia also facilitated via its National Electronic Tolling Committee representing all jurisdictions and toll road operator interoperability of toll tags in Australia for the multi lane free flow tolls roads.
Other systems that have been used include barcode stickers, license plate recognition, infrared communication systems and Radio Frequency Identification Tags.
Reference:
- Intelligent Vehicle Technologies, LLC-Where Innovation Intelligence and Technology meet the Road Ahead
- Simple Intelligent Electronic Solutions-Give us your Concept or Problem and we'll Develop the Solution
- lnnov ITS: UK Centre of Excellence for Transport Telematics and Sustainable Mobility
- Making Vehicles and Highways Intelligent
- International, Benefits, Evaluation and Costs Working Group for the ITS community
- National German interest group
- Journal of Intelligent Transportation Systems
- International Journal of Sustainable Transportation
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