Imagine buses running as fast on a road filled with traffic as they would if roads were empty. Buses do not stop at red lights and they are not breaking the signal. Sounds like a riddle, but this is what is happening in the United States and Canada these days.
A unique method of road travel, which is the dream of every commuter, is now made possible. Bus routes have been equipped with wireless technology, which turns a red light to green – “on command.”
As the buses reach an intersection, signal lights either turn green from red or stay green a few minutes longer. This way the buses do not have to stop and continue to travel fast. This method is said to be environment friendly as there is less pollution and more fuel savings, all because of lack of idling.
This unique technology that is called the “signal preemption,” can only be used by vehicles that are equipped with a GPS link and radio transmitter. The vehicle relays its location and speed to a computer that controls the traffic light. The light switches to green as the vehicle approaches the signal. Emergency vehicles can set up more green lights as they go.
This technology is already being used in ninety-eight metropolitan areas in the United States, in more than 30000 intersections. At least 90% of all intersections are using this technology in some places, such as Bellingham, Washington; Syracuse, New York; Boise City, Idaho; and Eugene, Oregon.
Houston reports that after it introduced the signal preemption technology, the travel time for emergency vehicles that are equipped with transmitters has been reduced by almost 23%, which makes all the difference for emergencies such as patients with cardiac arrest. Since the emergency vehicles go faster, the need for fire stations on the route reduces, thus saving on construction costs.
This idea of the signal preemption technology was created almost as far back as in the 1970s, when 3M came up with a system that allowed emergency vehicles change traffic signals with pulses transmitted to receivers fixed above the roadways. Some cities could not integrate the preemption technology into the old traffic light controllers. But the fact remains that the technology worked well.
Later, in the year 1979, 3M came out with advanced technology that was sold under the brand, Opticom, where it allowed for two levels of priority; a higher level for emergency vehicles, which allows them to change traffic lights immediately and a lower level for other vehicles, which can afford to wait if changing the light completely meant problems.
As is wont to happen, hackers got hang of the technology, and they began misusing it with the use of mail-order infrared transmitters that switch red lights to green. This is when 3M started adding encryption codes to stop all these monkeyshines.
The latest Opticom advancements make it possible to even pinpoint the location and speed of the vehicle. When a bus with GPS nears an intersection, it can take over the traffic light, and the computer also calculates the expected time of arrival and decides whether to give a green light or reduce the length of the red light. It also checks if the turn signal of the bus is on and decides whether to turn the left arrow or right arrow green.
Buses that have GPS can also tell the computers whether they are behind or ahead of schedule and also if there are any passengers onboard. However, empty buses and those buses that are ahead of schedule will have to wait at the red light just like other vehicles.
The GPS system from Opticom costs $5300 for every intersection and $3000 for each vehicle. Canadian firm Torquest bought this Opticom unit for $80 million last year from 3M.
Cities that are fast growing have totally taken to the new technology as it saves them a lot of money and has proved to be extremely useful too. It is really amazing how much difference a green signal makes.