LEXINGTON — Lexington’s automated traffic-light system, which became fully operational in November after 10 years of installation, is already being credited by town officials with having helped ease notorious traffic congestion in one of South Carolina’s fastest-growing cities.

The new system uses cameras and Bluetooth technology to identify congested areas, and feeds the data to an artificial-intelligence algorithm that continuously adjusts stoplight timing to direct the flow of vehicles. Traffic lights at all major intersections in Lexington, a 24,000-resident town 20 miles west of Columbia, are now equipped with the technology.

The technology also has been applied outside of the town limits to lights stretching northeast along Sunset Boulevard into West Columbia, a move that could move traffic more swiftly in an emergency, advocates said.

“Before I got elected, I would ride through this town,” Lexington Mayor Steve MacDougall said. “I would say that this is the least productive place in America, because nobody was working. Everybody was in the street. Everybody in Lexington was in their car.”

Heavy traffic through Lexington’s downtown has long been one of the town’s biggest headaches for residents and commuters both, and the town council committed many years working to mitigate the issue in the town.

But not everyone is a fan of the new system.

Despite its apparent success in its early months, the system contributes to an increasing amount of surveillance by government entities, and poses a threat to civil liberties and privacy, said Jace Woodrum, executive director of the American Civil Liberties Union of South Carolina.

Responding to traffic woes

In 2012, Lexington Council faced pressure to address mounting traffic problems as the town’s population and business scene continued to rapidly expand. The town’s population grew by 32 percent in the past decade, three times the state average and 21st fastest in South Carolina, according the Census data.

“I grew up in this town, and when I was 12, 13, 14 years old, I’d ride a bicycle alone down (Sunset Boulevard),” MacDougall said. “But today … almost 50,000 cars a day (drive) down that road.”

Because most of Lexington’s roads are owned by the S.C. Department of Transportation, and repaving and redesigning roads was too expensive for the town’s $9 million budget, Lexington council members needed to be creative with their solution to reduce traffic, MacDougall said.

After hearing at a conference about In-Sync Traffic Bot, the artificial intelligence system that now runs Lexington’s traffic lights, MacDougall went to Augusta, which had already installed the technology.

“We saw it work during Masters week,” MacDougall said referring to Augusta’s famed golf tournament. “It was amazing. There’s half a million people down there at one intersection in Augusta, Georgia, to see that golf tournament. … But we’re riding through the streets and we’re just zipping along.”

How the system works

The cameras installed at each traffic light count the number of cars piling up at a red light. When it counts too many, it will turn the light green. If traffic flow is heavy on a major thruway, cars on crossover streets might have to wait longer than they would on a traditional timer based light system, but nasty traffic jams on major roads will be mostly avoided, Lexington Transportation Director Randy Edwards said.

The cameras do, however, count how long a car waits, and eventually the light will stop traffic on thruways to let cars on side streets out, Edwards said.

In addition to the cameras, a Bluetooth system called Blue TOAD installed in each light tracks the phone number of a phone in each car.

If the number takes longer than average to get from one light to another, the system knows that traffic is moving too slowly and can adjust the traffic lights’ timing, Mac- Dougall said.

Both the cameras and the Bluetooth feed into an artificial-intelligence algorithm, which will learn the town’s traffic patterns and perfect Lexington’s traffic light system over time.

For example, on a Friday night, the lights might know that traffic will be heavy outside of high schools at the end of a football game, and so each week it can plan for heavier traffic at those intersections, Edwards said. If the traffic doesn’t come, the system will default to a more normal light cycle, he said.

Shortly after visiting Augusta, Lexington began installing its own automated lights at the town’s major intersections.

Outfitting the entire town totaled between $6 million and $7 million by the time installation was complete in 2022.

Traffic help in demand

In 2017, about 60 percent of traffic lights in Lexington had been equipped with artificial intelligence when Lexington Medical Center approached the town and asked for help clearing traffic on Sunset Boulevard, which blocked emergency vehicles’ access to the hospital.

Lexington agreed to install lights in front of the hospital, and the hospital agreed to pay to maintain them. But, because the DOT installs lights in groups, to update the technology in traffic lights outside of the hospital, Lexington would have to do the same for lights down Sunset Boulevard through Lexington County and West Columbia, ending just across the U.S. 1 bridge from Columbia.

“We felt strongly enough that the system was going to eliminate the issues they were having, and felt like we really wanted to be a community partner with them,” Mac- Dougall said.

The extra effort to extend automated traffic lights toward Columbia allowed the creation of an evacuation route from or to the city. In an emergency, Lexington officials can override the traffic light’s automated patterns and turn every light on Sunset Boulevard green from West Columbia to the Western side of Lexington, and allow for a steady flow of traffic out of Columbia to Lexington County, or vice versa.

By November, all major intersections in Lexington were equipped with the updated traffic technology.

Lexington did not make an announcement when the installation was complete, because the system was in its learning phase, MacDougall said. The town wanted to give the system time to learn traffic patterns, he said.

In the months since, the town has seen a 25 percent improvement in the towns’ traffic flow, MacDougall said. During the holidays, the system accommodated added traffic downtown, and adjusted for it properly, Lexington spokeswoman Laurin Barnes said.

Privacy red flags

Despite the technology’s impressive record so far, the system raises privacy red flags because it contributes to a pattern of the government using more surveillance to collect data, Woodrum with the ACLU said.

“I think it’s fair for the public to have questions about what is being done with this data,” Woodrum said.

“Now for most of us, we would want data to be collected and used to improve traffic patterns. What becomes a concern is personally identifiable information and then the security of this information.”