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Why You Wait Too Long at Red Lights, and What to Do About It

I've always detested waiting at red lights, especially when the person in front of me takes too long to start moving when the light changes.

Why does it take so long for traffic lights to turn green, and can anything be done about it?

Why does it take so long for traffic lights to turn green, and can anything be done about it?

Does the Light Take Forever to Turn Green?

Let's face it—everyone hates waiting at red lights. However, in many cases, it is the drivers themselves who are responsible for the long wait, because they do not understand that most traffic signals are now run by sensors and computers. By understanding how traffic sensors and traffic computers control the change of signals, you can help ensure that everyone waits less at red lights.

Worse than the time lost waiting, all those waits at traffic signals mean that you are spending more for gas, and you are experiencing more stress, which costs you more at the doctor's office, too! And frequent stopping is harder on your brakes and transmission, and idling at traffic signals causes pollution, which again, means more money at the doctor and less money for you.

This article may seem to be a little technical, but if you take the time to read through it, you will be more than repaid with the time saved not waiting for the light to change any longer! The savings of time, health, and money are worth the few minutes you invest in learning how traffic signals work and how your driving habits control how long the wait for the light to change will be.

This is a traffic sensor—a detector loop buried in the pavement that sends signals to the traffic control system.

This is a traffic sensor—a detector loop buried in the pavement that sends signals to the traffic control system.

How Traffic Signals Work

Although detector loop systems are how most traffic signals function nowadays, some traffic signals are still on fixed time or operate with pressure plates.

Fixed Time

Some traffic signals are on a fixed time. In this case, there is one remedy for waiting too long at red lights. You can contact your city, county, or state Department of Transportation and request a signal review, or you can go to a website called "See, Click, Fix" which will automatically report the problem to local authorities. (This website is also great for any kind of local problem such as potholes, code violations, and much more.)

A review of different traffic signal retiming projects throughout the U.S.A. and Canada revealed that by retiming traffic signals, delays could decrease by 13 up to 94 percent! The Traffic Light Synchronization Program in Texas reduced red light delays by 24.6 percent.

In my case, I reported a mistimed traffic signal, and within weeks the city was at work fixing it. When the fix was not sufficient, I posted a video of traffic blocking driveways to apartments and pointed out that emergency vehicles could not enter apartments. The city came out and fixed the timing again, and now I have very short waits at that signal.

Pressure Plates

A few intersections still use pressure plates. This works just like the automatic door opener in many supermarkets, and the best way to ensure that the signal is sent to the traffic control panel is to slowly roll your tires onto the pressure plate and let them rest there. (A pressure plate looks like a large, rectangular metal plate in the roadway.)

Detector Loop System

However, almost all modern signals use a detector loop system. For a signal to be sent to the traffic control panel, this requires that the presence of metal cover the entire loop for a certain period of time (otherwise, it would register passing traffic as waiting for the light to change).

Since most drivers either do not know how detector loops work, or ignore the knowledge, then they do not position their cars properly on the detector loop, and the loop does not register the presence of their car. When the loop cannot detect your car, it cannot send a signal to the traffic control panel that you are waiting at the red light, and therefore the light will take forever to change. It's really that simple!

Why Detector Loop Systems Aren't Foolproof

So why don't the detectors work better? I took a three-month survey every time I was stopped at a red light. More than three-quarters of the drivers I observed did not position their cars over the loop detector, so the signal was never sent to the traffic control panel.

Drivers pulled either far ahead of the stop line so that the rear of their car was not aligned with the rear of the detector loop, and therefore the detector loop decided that their car had already passed through the intersection, or the drivers stayed too far behind the line so that the detector loop signal from the front to the back of the loop did not complete.

As a result, everyone was sitting and waiting at the traffic signal—and often, the people who were most annoyed were the people who were causing the problems!

Where to Position Your Car so the Red Light Will Change

To properly position your car over the detector loop, you need to understand where the loop is. In states with "stop lines" (a wide white line in front of the pedestrian crosswalk), the detector loop usually begins two feet behind the line.

To make sure the loop is entirely covered, the best place to position your car is with your front bumper, approximately one foot to 18 inches behind the stop line. This way, the detector loop will detect your car motor over the loop, and it will send a signal to the traffic control panel that your car is waiting.

Note that although in the photo above, the loops are circular, this is not always the case. Detector loops can also be oval or rectangular; therefore, it is best to stay in the middle of the lane and use the stop line or pedestrian crosswalk to adjust the position of your car. If, as often happens, the detector loop is put in after the road is completed, cuts in the pavement will tell you exactly where to position your car.

A broken traffic signal

A broken traffic signal

How to Avoid Red Lights Altogether

If you are stuck at a red light, you certainly don't want to be stuck at the next one! How do you avoid getting stuck at red light after red light?

There's one very simple answer to this: when the light turns green and you begin driving, accelerate slowly and smoothly up to the speed limit. Then drive the speed limit.

Why does this work? Traffic signals tend to be timed in sequence so that if you make one green light, you will make them all. (This won't always be the case, as some parts of traffic grids do not communicate with other parts of traffic grids.) But, as you go through a green light, take a tiny amount of time to notice the pedestrian signal.

If pedestrians have a "walk" signal or the signal has just turned to "don't walk," keep driving exactly the speed limit. If the "don't walk" signal has been there a little while, drive about a half-mile per hour over the speed limit to the next light, then continue at exactly the speed limit. You do not need to speed; in fact, going over the speed limit will make you wait at a red light.

I'm sure everyone feels this way at one time or another!

I'm sure everyone feels this way at one time or another!

I Know All This, But It's Those Other People That Are the Problem!

There's a simple solution to educating all those other drivers, too! Simply start sharing this article with everyone you know who drives a car, and as the word gets around, more and more drivers will begin to understand how the position of their car at a red light, and their speed, will enable them to spend far less time waiting at red lights.

As Thomas Hobbes wrote back in 1658, "Knowledge is power." And there you have it. The problem of waiting too long for the traffic signals to change will be solved, everyone will be happier, and they will save money, too!

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2011 classicalgeek