UH engineer: Speedier traffic lights could alleviate congestion

UH engineer: Speedier traffic lights could alleviate congestion

HONOLULU (HawaiiNewsNow) - The time it takes for a red light to turn green and then yellow and then back to red is called a cycle.

And each cycle takes a certain amount of time.

Traffic planner Panos Prevedouros is proposing those cycles be sped up -- and he argues fixing Oahu's "sluggish" signals could make a significant positive impact on traffic.

"We just need to make our signals more snappier," he said.

Prevedouros, chairman of the University of Hawaii's Civil and Environmental Engineering Department, said shortening a signal's cycle by just five seconds would speed up traffic. He's tested his theory in a computer simulation, and he believes it would work in the real world.

"It's a little thing, five to 10 seconds, but it makes a big difference on the aggregate," he said. "It's much quicker and you pump more cars through this intersection. Everybody gets home quicker."

Prevedouros said traffic signals waste time when they're green and no cars are there. In the meantime, cars on intersecting streets are stuck at red lights.

Plus, he argued, his "five-second rule" could be implemented quickly on busy streets and highways by reprogramming sensors embedded in the blacktop. "It's very easy to change the settings and make the signal more responsive," he said.

But the city's Transportation Services Department stands by its system. Operators do remotely adjust some signal's cycle lengths during rush hour and emergencies.

Student engineers who study transportation at UH, meanwhile, think Oahu's traffic signals could be more effective.

"Some of them are just out of date. Their timing plans are too short or they don't account for new left turners," student Nicki Shobert said.

"Maybe a few of them don't have the right green waves," student Shaun Lorenzo said. "Sometime you'll get caught in red lights instead of getting green all the way."

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