Adaptive Traffic Signals Control

“When it feels; it deals.”


One day, I was on my way to a very important interview. I left home very early to arrive on time. I was wondering, when the traffic will be smooth and stop wasting our time! When I arrived home, I started to search for a solution. Luckily, I found a scientific solution that civil engineers applied in America. This solution is called “Actuated Traffic Signals Control”.


The idea simply is: Each intersection contains detectors, which record the traffic volume and send a signal to the controller with the actual information. The controller changes the phase lengths to correspond to this signal without affecting on other intersections. This system depends on historical data in designing the phase lengths.


This system is divided into two sub-systems: Fully Actuated and Semi-Actuated. The fully actuated System puts the detectors on all sides of the intersection, whereas the semi-actuated put them only on two opposite sides of intersection. The choice depends on the need of the intersection. If it contains two major streets with approximate flows, then it will require a fully actuated system. And if it contains major street intersect with minor street it will require a semi actuated system. Using fully actuated system saves citizens’ money, but as I said, we choose the system according to our need.


The other solution is called “Adaptive Traffic Signals Control”. It is a modified copy from the actuated system. It deals with real time; it uses the present data to predict the crowding time and deals with cycle lengths.


To clarify the difference between the two systems read this example. The traffic volume now is huge compared to normal; the detector records this information and sends it to the controller. The controller, in turn, changes the red light to green and modifies the total phase length to keep the balance of traffic volume. This is an “Adaptive Traffic Control System” which depends on the actual time. In an “Actuated Traffic Control System” the controller designs the traffic lengths due to past information. The detectors are put to record the flow to develop the design of cycle length.


Back to my real life, I started to wonder how and when I can see this technology around us. I believe that we have the scientific basis to convert the current system into a smart automated one using sensors and prediction. And we have researches and many applied examples that we can learn from. The next step is to start implementing these solutions we know of into real life. This will only happen when we do appreciate the value of time. Until then, try to invest the time you spend in transportation in something that adds value to your life.


This Post is posted by Abdelrahman El-Adawy

An IEEE AlexSB Volunteer, R&P Committee.

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