Mobile Infrared Transmitter
Encyclopedia
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.
circuit connected to an infrared
LED
array. The timer causes the infrared LEDs to strobe at specific frequencies, such as 10Hz
for low priority (buses) or 14 Hz for high priority (emergency vehicles)http://www.themirt.com/. Low Priority transmitters will control the intersection to perform a normal light change, while High Priority tramsitters will change an entire intersection immediately http://www.themirt.com/.
It is a federal offense in the United States for an unauthorized person to use any traffic preemption device. This is due to the Safe Intersection Act of 2005.
Traffic
Traffic on roads may consist of pedestrians, ridden or herded animals, vehicles, streetcars and other conveyances, either singly or together, while using the public way for purposes of travel...
preemption device that city buses and emergency vehicles use to control the traffic control equipment
Traffic light
Traffic lights, which may also be known as stoplights, traffic lamps, traffic signals, signal lights, robots or semaphore, are signalling devices positioned at road intersections, pedestrian crossings and other locations to control competing flows of traffic...
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 timerTimer
A timer is a specialized type of clock. A timer can be used to control the sequence of an event or process. Whereas a stopwatch counts upwards from zero for measuring elapsed time, a timer counts down from a specified time interval, like an hourglass.Timers can be mechanical, electromechanical,...
circuit connected to an infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
LED
Light-emitting diode
A light-emitting diode is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting...
array. The timer causes the infrared LEDs to strobe at specific frequencies, such as 10Hz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
for low priority (buses) or 14 Hz for high priority (emergency vehicles)http://www.themirt.com/. Low Priority transmitters will control the intersection to perform a normal light change, while High Priority tramsitters will change an entire intersection immediately http://www.themirt.com/.
Usage restrictions
Certain cities use specially encoded infrared pulses to prevent the use of home made transmitters.It is a federal offense in the United States for an unauthorized person to use any traffic preemption device. This is due to the Safe Intersection Act of 2005.