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Engineering efficiency: the unseen efforts behind Alabama’s traffic signals

Jul 19

Traffic signal efficiency is revolutionizing the way drivers experience their daily commutes.

Menasse Kumlachew, the Signal Systems Engineer with the Alabama Department of Transportation’s West Central Region, is behind the scenes monitoring traffic signals for any issues or alerts from motorists.

Kumlachew can direct technicians to fix flashing signals, adjust signal timings and update signal coordination all from inside his office. However, it’s not an easy job, as one signal impacts another since most traffic signals in urban areas are within a radius of less than a mile.

“Coordination and optimization help us use our existing infrastructure more efficiently,” said Kumlachew, a 10-year ALDOT veteran. “Most of what we do involves cities, and we work very close with them. These partnerships are very important, and it would not be possible without their help.”

Kumlachew and his fellow signal systems engineers strive to anticipate and resolve problems before drivers notice them.

Traffic optimization begins by counting the average number of cars passing through an intersection during an average day and feeding the data into a model. The models typically get the traffic signals to around 80% optimal timing. To reach 100%, technicians visit the sites to fine-tune signals.

Field visits are still crucial because they allow technicians to spot details that cameras or sensors might miss and to understand the physical space better. Additionally, smart signals at intersections use cameras, pavement-embedded cables and surface devices to send and receive information, enabling traffic to move as efficiently as possible.

“Getting ahead of potential issues and fine-tuning signals on-site makes a huge difference in the flow of traffic,” Kumlachew said.

Traffic signal optimization has vastly improved over the past decade in Alabama. Eight years ago, few signals were online and cameras were just being installed, making the job much more difficult. Issues are identified much quicker today and technicians can adjust signals 83% faster than a few years ago.

Managing game day traffic has become increasingly important as the University of Alabama and the city of Tuscaloosa continue to grow. On game days, traffic signal technicians typically arrive four hours before kickoff to implement traffic management plans. Previously, it took five hours for traffic to clear out after games. However, with updated technology and consistent efforts, it only takes two hours.

“We have made many improvements in just a short period of time,” Kumlachew said. “I’m encouraged by what we do and what technology allows us to do. Our goal is to become even more efficient in the next decade.”