|
Mobile Infrared Transmitter
A Mobile Infrared Transmitter (MIRT) is an electronic traffic preemption device that city buses and emergency vehicles use to control the traffic control equipment for intersections they are approaching, in order to pass through the intersection as efficiently or safely as possible. Description A MIRT device consists of a timer circuit connected to an infrared LED array. The timer causes the infrared LEDs to strobe at specific frequencies, such as 10 Hz for low priority (buses) or 14 Hz for high priority (emergency vehicles). Low priority transmitters will control the intersection to perform a normal light change, while high priority transmitters will change an entire intersection immediately. Usage restrictions Certain cities use specially encoded infrared pulses to prevent the use of home made transmitters. People buying and selling the devices hit a roadblock in August 2005 when President George W. Bush George Walker Bush (born July 6, 1946) is an American po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traffic
Traffic comprises pedestrians, vehicles, ridden or herded animals, trains, and other conveyances that use public ways (roads) for travel and transportation. Traffic laws govern and regulate traffic, while rules of the road include traffic laws and informal rules that may have developed over time to facilitate the orderly and timely flow of traffic. Organized traffic generally has well-established priorities, lanes, right-of-way, and traffic control at intersections. Traffic is formally organized in many jurisdictions, with marked lanes, junctions, intersections, interchanges, traffic signals, or signs. Traffic is often classified by type: heavy motor vehicle (e.g., car, truck), other vehicle (e.g., moped, bicycle), and pedestrian. Different classes may share speed limits and easement, or may be segregated. Some jurisdictions may have very detailed and complex rules of the road while others rely more on drivers' common sense and willingness to cooperate. Orga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traffic Light
Traffic lights, traffic signals, or stoplights – known also as robots in South Africa are signalling devices positioned at road intersections, pedestrian crossings, and other locations in order to control flows of traffic. Traffic lights consist normally of three signals, transmitting meaningful information to drivers and riders through colours and symbols including arrows and bicycles. The regular traffic light colours are red, yellow, and green arranged vertically or horizontally in that order. Although this is internationally standardised,1968, as revised 1995 and 2006Vienna Convention on Road Signs and Signals United Nations Publication ECE/TRANS/196. ISBN 978-92-1-116973-7. URL Accessed: 7 January 2022. variations exist on national and local scales as to traffic light sequences and laws. The method was first introduced in December 1868 on Parliament Square in London to reduce the need for police officers to control traffic. Since then, electricity and computerised ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timer
A timer is a specialized type of clock used for measuring specific time intervals. Timers can be categorized into two main types. The word "timer" is usually reserved for devices that counts down from a specified time interval, while devices that do the opposite, measuring elapsed time by counting upwards from zero, are called stopwatches. A simple example of the first type is an hourglass. Working method timers have two main groups: hardware and software timers. Most timers give an indication that the time interval that had been set has expired. Time switches, timing mechanisms that activate a switch, are sometimes also called "timers". Hardware Mechanical Mechanical use clockwork to measure time. Manual timers are typically set by turning a dial to the time interval desired; turning the dial stores energy in a mainspring to run the mechanism. They function similarly to a mechanical alarm clock; the energy in the mainspring causes a balance wheel to rotate back and fort ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around 1 millimeter (300 GHz) to the nominal red edge of the visible spectrum, around 700 nanometers (430 THz). Longer IR wavelengths (30 μm-100 μm) are sometimes included as part of the terahertz radiation range. Almost all black-body radiation from objects near room temperature is at infrared wavelengths. As a form of electromagnetic radiation, IR propagates energy and momentum, exerts radiation pressure, and has properties corresponding to both those of a wave and of a particle, the photon. It was long known that fires emit invisible heat; in 1681 the pioneering experimenter Edme Mariotte showed that glass, though transparent to sunlight, obstructed radiant heat. In 1800 the astronomer Sir William Herschel discove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light-emitting Diode
A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corresponding to the energy of the photons) is determined by the energy required for electrons to cross the band gap of the semiconductor. White light is obtained by using multiple semiconductors or a layer of light-emitting phosphor on the semiconductor device. Appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared (IR) light. Infrared LEDs are used in remote-control circuits, such as those used with a wide variety of consumer electronics. The first visible-light LEDs were of low intensity and limited to red. Early LEDs were often used as indicator lamps, replacing small incandescent bulbs, and in seven-segment displays. Later developments produced LEDs available in visible, ultraviolet (U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strobe
A strobe light or stroboscopic lamp, commonly called a strobe, is a device used to produce regular flashes of light. It is one of a number of devices that can be used as a stroboscope. The word originated from the Ancient Greek ('), meaning "act of whirling". A typical commercial strobe light has a flash energy in the region of 10 to 150 joules, and discharge times as short as a few milliseconds, often resulting in a flash power of several kilowatts. Larger strobe lights can be used in “continuous” mode, producing extremely intense illumination. The light source is commonly a xenon flash lamp, or ''flashtube'', which has a complex spectrum and a color temperature of approximately 5,600 kelvins. To obtain colored light, colored gels may be used. Scientific explanation of flashtubes Strobe lights usually use flashtubes with energy supplied from a capacitor, an energy storage device much like a battery, but capable of charging and releasing energy much faster. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one hertz is the reciprocal of one second. It is named after Heinrich Rudolf Hertz (1857–1894), the first person to provide conclusive proof of the existence of electromagnetic waves. Hertz are commonly expressed in multiples: kilohertz (kHz), megahertz (MHz), gigahertz (GHz), terahertz (THz). Some of the unit's most common uses are in the description of periodic waveforms and musical tones, particularly those used in radio- and audio-related applications. It is also used to describe the clock speeds at which computers and other electronics are driven. The units are sometimes also used as a representation of the energy of a photon, via the Planck relation ''E'' = ''hν'', where ''E'' is the photon's energy, ''ν'' is its f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George W
George Walker Bush (born July 6, 1946) is an American politician who served as the 43rd president of the United States from 2001 to 2009. A member of the Republican Party, Bush family, and son of the 41st president George H. W. Bush, he previously served as the 46th governor of Texas from 1995 to 2000. While in his twenties, Bush flew warplanes in the Texas Air National Guard. After graduating from Harvard Business School in 1975, he worked in the oil industry. In 1978, Bush unsuccessfully ran for the House of Representatives. He later co-owned the Texas Rangers of Major League Baseball before he was elected governor of Texas in 1994. As governor, Bush successfully sponsored legislation for tort reform, increased education funding, set higher standards for schools, and reformed the criminal justice system. He also helped make Texas the leading producer of wind powered electricity in the nation. In the 2000 presidential election, Bush defeated Democratic incum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SAFETEA
Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users or SAFETEA-LU was a funding and authorization bill that governed United States federal surface transportation spending. It was signed into law by President George W. Bush on August 10, 2005, as and . History The $244.1 billion measure contained a host of provisions and earmarks intended to improve and maintain the surface transportation infrastructure in the United States, including the Interstate Highway System, transit systems around the country, bicycling and pedestrian facilities, and freight rail operations. The bill was named after Lu Young, the wife of Representative Don Young. Congress renewed its funding formulas ten times after its expiration date in 2009, until replacing the bill with the Moving Ahead for Progress in the 21st Century Act (MAP-21) in 2012. Support and opposition In 2006 Speaker of the United States House of Representatives, Dennis Hastert, championed a $207-million ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traffic Signal Preemption
Traffic signal preemption (also called traffic signal prioritisation) is a system that allows the normal operation of traffic lights to be preempted. The most common use of these systems manipulates traffic signals in the path of an emergency vehicle, halting conflicting traffic and allowing the emergency vehicle right-of-way, thereby reducing response times and enhance traffic safety. Signal preemption can also be used on tram, light-rail and bus rapid transit systems, to allow public transportation priority access through intersections, and by railroad systems at crossings to prevent collisions. Implementation Traffic preemption is implemented in a variety of ways. Traffic light activation devices can be installed on road vehicles, integrated with transport network management systems, or operated by remote control from a fixed location, such as a fire station, or by an emergency call dispatcher. Traffic lights are equipped to receive an activation signal which interrupts the n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
