Get IT Done - IT Is Stopping You (and letting you go

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IT Is Stopping You (and letting you go)

Get IT Done

We’ve all been there. We’re in a hurry and hit a red light [life is like that]. It is a long light and holds you immobile for a full minute. You wait. As the seconds slowly tick by, you feel yourself getting later and later. Most frustrating is that you are the only car at the intersection. In fact, you are the only car visible in any direction! A simple timer controlled that traffic light. While designed to provide equal access, timers often block progress unnecessarily. yell “It’s RED!”, as they think you are pressing them to run the light. Once, when I was in that situation, I exited my vehicle to explain how the traffic sensor worked to a very elderly couple. I conveyed that they either needed to move forward or spend the rest of what remained of their short life at that very spot. While that couple was grateful for the information, I will not do it again. People are wary when being approached by strangers at intersections.

Most timer-based controls have been replaced with units that “sense” vehicles. We install pressure plates under the roadways where the weight of a vehicle over the plates triggers a circuit that changes the light. Regrettably, if your vehicle does not weigh enough [E.G., a motorcycle or Smart Car] you may be waiting forever.

While pressure plates provide more efficient traffic control than timers, they can be expensive to manufacture, install and maintain. Here is where electromagnetic waves come to the rescue! “Induction loop technology” buries a loop of wire in the road and runs an electric charge through it, thereby creating a magnetic field. The presence of metal objects over the loop induces fluctuations in that magnetic field. These fluctuations then generate a signal to the traffic device. Induction loop technology is simpler to manufacture and install than pressure plates.

Both plates and loops are visible as squares, rectangles, or circles in the roadway at an intersection. Of course, unwary travelers may pull too far forward or remain too far back to trigger the sensor. This has caused me grave consternation in the past. One Sunday afternoon, late and in a hurry [again], I found myself stopped behind a car at a red light. That car had stopped well short of the traffic light’s sensor. I wait, minute after minute, hoping that they would edge up a bit. Disappointingly, they remained immobile.

What is the socially acceptable thing to do? Flash your lights briefly? Give a short toot of your horn? It turns out that these actions tend to anger the driver who will

get IT done Back to traffic control. Knowing that a car is at the intersection is helpful but does not provide feedback on how long to keep the light green. Cameras and infrared sensors see what is at an intersection as well as what is approaching. Knowing what is approaching (again, using our old friend electromagnetic waves) the light can be kept green to maintain traffic flow.

Having traffic devices that sense our presence and react accordingly is grand, but we may ask ourselves why we need traffic control devices at all? We need them because people do not behave in a reliable and predictable way. In the future, our vehicles will be autonomous devices bristling with more sensors than our most advanced traffic control systems. These vehicles will know where they are and where all other objects are to navigate the roadways without the need for traffic control devices. And that capability will be enabled by electromagnetic waves. IT will drive us into the future. Literally.

Think About IT!

Tony Keefe, COO, Entre Computer Services www.entrecs.com

NOVEMBER 2022 The ROCHESTER ENGINEER | 15