Gridlock Guy: Adaptive signals may fix some suburban traffic issues

One of the biggest, if not the biggest complaint that I hear from Atlanta commuters is the frustration over traffic lights that aren’t properly synced. I get it. There is nothing more annoying that sitting at a stop light, finally getting a green light, only to hit another red light just a couple of hundred yards down the road. The process is enormously frustrating.

Generally, it is up to local jurisdictions to properly time traffic lights on surface streets. Elected officials and traffic engineers understand that this is a major issue and usually try their best to make improvements and/or corrections. Finally, it seems, technology might be progressing to the point where we could actually see “smart” traffic signals.

The proper term is “adaptive traffic signals” and they are starting to gain popularity around the country. What exactly is an adaptive traffic signal? Basically it has the ability to adjust the times of red, yellow and green lights depending on traffic conditions.

If there are extra delays, the light can stay green longer, allowing more traffic to flow.

“Adaptive signals make sure inefficiencies never happen,” Alex Stevanovic, director of the Laboratory for Adaptive Traffic Operations & Management at Florida Atlantic University said. “They can make sure that the traffic demand that is there is being addressed.”

The adaptive signals gather information from wires that are embedded in the road that are able to determine how much traffic is moving toward and through an intersection. When traffic increases, the adaptive signals stay green longer. When traffic is lighter, the signals go back to normal settings.

Bellevue, Washington is one city that is embracing the “smart” traffic signals. The city, with 130,000 residents outside of Seattle has seen some travel times decrease by 36 to 42 percent during rush hour since the smart signals were installed.

“It’s been a slow change,” said Mark Poch, the Bellevue Transportation Department’s traffic engineering manager. “It’s easy to think the way to get out of it is to widen the road. However, as we move toward being better stewards of our resources and more sensitive to environmental issues, let’s take what we have and operate it better. I think that’s a more prevailing thought now, and I think it makes sense.”

Currently only three percent of traffic signals in the United States are adaptive, but the number is growing. Between 2009 and 2014 the number of smart signals in use increased from 4,500 to 6,500.

While these smart lights might help traffic flow, they shouldn’t be considered a solution for all traffic woes.

“It’s not going to fix everything,” Kevin Balke a researcher at the Texas A&M University Transportation Institute said. “But adaptive has some benefits for a smaller city with a particular corridor on the verge of breaking down.”

Here in metro Atlanta, I think we could see the greatest benefits of adaptive traffic signals outside of the perimeter (Kennesaw, Alpharetta, McDonough, etc..). As populations and traffic continue to grow, smart signals could be a part of larger plan to help things more move smoothly.