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Intelligent Transportation SystemsMaking highways smarter and safer
Highway congestion is routinely cited as being among the biggest problems facing American metropolitan areas. Today, vehicles in cities and urban counties can average speeds as low as eight miles per hour during rush hours. Since 1960, highway travel has nearly quadrupled, with more than two trillion vehicle miles being driven each year in the United States. Traffic delays cost $120 billion per year, and nearly 40,000 people die in traffic accidents annually. An intelligent highway infrastructure is needed that can help speed up travel and improve safety by using optoelectronic and RF/Microwave components in a variety of systems. Wireless applicationsCurrently, HP RF semiconductors are being used in cellular telephones, GPS receivers and automatic toll tags. In the future they will be utilized in two-way vehicle-to-roadway and infrastructure communications links that are a part of intelligent highway systems. Such links will assist in traffic flow management by providing vehicle position data and road conditions to a central traffic management center, which then can vary signal timing, recommend alternative routes to motorists and monitor congestion levels.HP infrared transceivers offer an alternative approach to short-distance data communications for downloading maps and other navigation information to vehicles, and for providing vehicle identification information to the “smart” highway infrastructure. Both RF and infrared transceivers can be used in today’s highway applications such as vehicle identification for automated toll collection. HP also supplies components such as GaAs diodes, transistor and RF integrated circuits for use in radar-like microwave-frequency assisted braking, intelligent cruise control, and collision avoidance systems. Highway message signsHP’s amber LEDs are ideally suited for displaying cautionary traffic messages. For overhead traffic message signs, the superior reliability of LEDs over incandescent bulbs and mechanical flip discs significantly reduces maintenance costs associated with sign servicing and repair, thus reducing the operating budgets of the responsible municipality. In addition, an LED sign is less likely to have unlit segments causing the sign to transmit illegible traffic messages which can result in driver confusion.For portable and temporary advisory and warning signs, such as those used at highway construction sites, LED signs consume substantially less electrical power than signs using incandescent lamps. Capable of being powered by solar cells, LED signs eliminate the noise, expense and pollution associated with diesel-powered electrical generators. Pedestrian and traffic signalsRed LED traffic signal heads are currently being installed world-wide. Amber LEDs of equivalent brightness are already available, and green LEDs, enabling a full LED tricolor traffic signal, will be available in the near future. It has been estimated that a large city of 2900 intersections, serviced by LED traffic signals, will save 12 million kilowatt hours in electrical costs and $1.2 million in maintenance costs. The amount of airborne emissions of carbon dioxide and nitrous oxides produced by power generating stations would be reduced significantly.Product SummaryIntelligent Transportation Systems
- 5 mm AlInGaP LED Lamps
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