Which of the following is used to change traffic lights for emergency vehicles?
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The Safe Intersections Act, part of the transit bill signed Wednesday by President Bush, makes it a misdemeanor for unauthorized users to wield a "traffic signal pre-emption transmitter," a special remote control used by police, firefighters and ambulance drivers to change traffic lights to green as they approach an intersection. Show Lawmakers took an interest in the devices, called mobile infrared transmitters, or MIRTs, a couple of years ago, when it emerged that impatient commuters could purchase rogue boxes online for around $500. Several states outlawed unauthorized possession of the transmitters, and Sen. Mike DeWine (R-Ohio) introduced the federal bill in 2003. The measure won support from police and firefighter groups. "When you first look at it, you think, 'It's not such a big deal,'" says DeWine spokesman Jeff Sadosky. "But when you realize the possible implications, somebody using one of these to go 80 miles an hour through rapidly changing lights, you realize it could be life-threatening." Selling a device to an unauthorized user can land the vendor up to a year in prison; using an MIRT without authorization will carry a penalty of up to six months. "We agree with the provision," says Gerald Donaldson, senior research director with Advocates for Highway and Auto Safety. "We see how (MIRTs) can be used by people who pose a security threat to American institutions and people." At first blush, the new law would seem to be a red light for companies like Beeco Sales, which sells an aftermarket transmitter called the Stealth EVP, a tiny emitter that can be clipped to a windshield visor like a radar detector or mounted invisibly behind the grill of a car. But company owner Bruce Erichsen says his network of dealers only sells to authorized governmental users -- the stealth model is for undercover cops, he says. "I don't want them in the wrong hands," says Erichsen. "I want the police and fire departments in small towns who can't afford what my competitors charge to be able to have pre-emption. It saves lives." Starting at around $250, Erichsen's MIRTs are still not the cheapest option. Last month, the hardware hacking site I-Hacked.com published plans and instructions for building a home-brew MIRT with a handful of parts totaling less than $20. Site owner Bill Swearingen, a Kansas computer security specialist, says he learned everything he needed to design the circuit from the web. "It's very simple to build," he says. The devices are essentially infrared strobe lights, says Swearingen. They flash at one of two particular frequencies -- a low-priority frequency used by mass transit just keeps a green light green a little longer. The other, high-priority frequency is for emergency vehicles, and it flips red lights to green, initiating the change cycle within two seconds of activation. Swearingen says he tested his proof-of-concept device on the streets of Kansas City with complete success before disassembling it to avoid trouble. "I take the freeway to work," he says. "There are no traffic signals." He criticizes equipment makers for not building some kind of authentication into the devices. "Traffic lights are critical systems," he says. Donna Fleming, spokeswoman for 3M, says the latest generation of the company's Opticom pre-emption system has a security option that allows cities to program their traffic lights to respond only to an infrared signal that pulses an authorized serial number. "Your emitter is programmed into it, so when you trigger this system it recognizes you as an authorized user," Fleming says. "All the systems that we sell have that feature." Maryland is one of the states embracing the newer equipment, says Thomas Hicks, traffic safety director at the Maryland Department of Transportation. "All of our fire equipment and emergency equipment will now have a coded signal, and the traffic signal itself will have a coded receiver," he says. The state is swapping in the newer, more secure equipment, a process that he says will be done by the end of 2006. Replacing all the systems nationwide would be a large undertaking. A 2002 Department of Transportation survey found pre-emption systems in use at nearly 25,000 intersections across the country. The newer systems can also be programmed to log every activation, a useful feature for finding rogue MIRTs, says Hicks. "There will be periodic checks into the number of uses, and if you see spikes in the number of signals, you begin to wonder why," he says. Emergency and mass transport vehicles are equipped with devices that turn traffic lights green, if you have a yen to do the same, you could be in big trouble. Marcia Wendorf | Dec 06, 2019 10:03 AM EST Created: Dec 06, 2019 10:03 AM EST innovation iStockPhotoAbabsolutum/iStock You're sitting at a red traffic light wishing it and all its brethren in front of you would turn green. It turns out that during the wild and woolly aughts, you could actually make this happen. The process is called traffic signal preemption, and it's been around for over 20 years. Emergency vehicles have used it as a way to get to incidents quickly by halting conflicting traffic and giving themselves the right of way. See Also RELATED: 11 FUTURISTIC TRAFFIC LIGHTS THAT COULD MAKE ROADS SAFER Traffic signal preemption is also used by light rail and bus rapid transit systems, and by railroad systems at level crossings. The system is used near fire stations to change traffic lights in order to allow emergency vehicles to exit the station. How it worksTraffic lights must be equipped with a receiver, and a vehicle, bus, train or fixed building must be equipped with an emitter that produces either visible flashes of light or invisible infrared pulses at a specified frequency. Infrared pulses are created by a Mobile Infrared Transmitter (MIRT) that consists of a timer circuit and an infrared LED array. The infrared LEDs can strobe at 10 Hz for low priority vehicles, such as buses, or at 14 Hz for high priority vehicles, such as fire trucks. They will work from up to 1,500 feet away from a traffic light. In the U.S., two major companies, 3M and Tomar Electronics Inc., sell traffic signal preemption devices. Some traffic signal preemption systems include feedback for both emergency vehicles and other drivers that a traffic signal is under the control of a preemption device. Most Popular Called a "confirmation beacon", it is an additional light located near the traffic signal that either flash to tell drivers to stop, or stays on to tell drivers from what direction the emergency vehicle is coming. Newer traffic signal preemption systems include a security feature that requires a serial number to accompany the emitter's signal. These newer systems also keep track of every time a traffic signal is activated, so with the addition of a traffic camera, finding unauthorized users isn't hard. If you aren't afraid of prisonIn the mid-2000s, you could buy MIRTs openly on eBay, then in August 2005, the Safe, Accountable, Flexible, Efficient Transportation Equity Act was passed. It set a minimum sentence of six months in prison for anyone using the devices, and a year in prison for anyone selling the devices. Surprisingly, we found that you could still buy traffic signal preemption devices online, and we found the internet to be awash in videos showing how to create one of the devices yourself. Youtube user VolteGe, who says he is too young to drive, has nevertheless created a MIRT controlled by an Arduino microcontroller. And, according to Youtube user frost5000000, you can change traffic lights to green just by using your cellphone. User Dane Boe shows how to create an emitter using a TV universal remote control. According to website boingboing.net, a Longmont, Colorado man was fined $50 when police identified his white Ford pickup at the site of numerous traffic preemptions. Commenting on the site, a traffic engineer said that the use of signal preemption equipment was very common in Northwest states such as Oregon where receivers are installed at 80% of intersections. Finally, it is an urban legend that you can strobe your car's high beam lights to activate traffic light preemption. You would need to flash them at a rate of 10 to 15 flashes per second which would be difficult at best.
For You science ‘Let’s build the ring’: How a 360-degree image posted on Facebook inspired an ambitious sci-fi film Hashem Al-Ghaili, the scientist and viral video creator, talks about his upcoming science-fiction feature film "Orbital". Which of the following is used to change traffic lights for emergency vehicles ITCS IoT Car Smart Car IoT sensor?Which of the following is used to change traffic lights for emergency vehicles? EXPLANATION The Smart Ambulance Service system (SAS system) uses the Intelligent Traffic Control System (ITCS) to automatically control the timing of traffic lights that are in the path of emergency vehicles.
Which of the following is considered an IoT device?The IoT devices include wireless sensors, software, actuators, computer devices and more.
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Which frequencies does Zigbee operate on?This technology can be operated at 868 MHz, 902-928 MHz, and 2.4 GHz frequencies depending upon the requirement of application; whereas, the data rate of 250 Kbps is best suited for two way communication between several sensors nodes and controllers.
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