By Aaron Blevins, 5/03/2012
During rush hour on a weekday, one might expect the traffic control center in downtown Los Angeles to be a frantic, frenzied place. One might envision workers with disorderly, graying hair jogging in business attire, dodging airborne sheets of paper.
However, even with last week’s rain, the atmosphere at the Automated Traffic Surveillance and Control (ATSAC) center at City Hall East was calm and quiet, the silence interrupted only by strokes of a keyboard and radio traffic.
A traffic signal last Thursday was knocked out at Highland Avenue and Olympic Boulevard, likely due to standing water. The engineer on duty, Maurice Camacho, used a camera on La Brea Avenue to zoom in on the intersection and then radioed for a repairman. Some motorists were impacted by the outage, but the light quickly returned. Fire extinguished.
The center and the system were birthed in preparation for the 1984 Olympics. Since then, the two have been utilized to mitigate the city’s infamous rush hours to the best of their abilities, dispatching repairmen and traffic officers when needed. But in a spread-out city with nearly 4 million residents, congestion is certain like death and taxes.
“There’s a certain threshold for what we can do,” said Los Angeles Department of Transportation engineer Ed Yu, who oversees ATSAC. “I always tell people there are winners and losers in traffic. It’s a balance. …A lot of times — I hate to say it — there’s nothing I can do. It’s all about balance.”
In its 28 years, the system has accumulated real-time data for almost 4,500 intersections, with approximately 400 of them wielding cameras that zoom and rotate. The center has software that provides a graphical representation of each intersection they control and key elements of that intersection. This information is compiled from sensors in the street called “magnetic inductor loops.”
The “loops” forward information such as speed, volume, occupancy and “cycle length” back to the center. It also relays “allotment times,” which determine how long a particular direction receives a green light at intersections. Those allotment times combine to calculate the signal’s cycle length.
“We have different levels of occurrences,” Yu said. “As [traffic] changes, the system will sense there’s high demand there and make an adjustment. We can [also] modify all these parameters manually.”
Therefore, if there is a major incident backing up traffic, operators such as Camacho can ease congestion by changing allotment times as needed. Oftentimes, such adjustments are made in response to construction, malfunctioning signals, car accidents, criminal activity or weather-related incidents.
“We have a lot of capabilities,” Yu said.
On Thursday, construction continued on the bridge near Mulholland Drive and Skirball Center Drive. The work, though, has been ongoing, and Camacho did not alter any lights to ease the flow of traffic. Yu said operators try not to overreact, as a change to the intersection also affects the system as a whole.
“Sometimes, you have to let it work itself out,” he said.
Generally, there are just one or two operators on duty during the center’s business hours, 6 a.m. to 7 p.m., Monday through Friday. For major incidents or events, such as marathons, natural disasters and “Carmageddon”, as many as 20 operators could be available, Yu said.
The system also makes special accommodations for busses and light rail trains. Yu said the Los Angeles County Metropolitan Transit Authority (Metro) had reached out to ATSAC to cut Orange Line bus times, and the ATSAC engineers added transponders to the busses and gave them priority in the system. Now, signals know if a bus is behind schedule, Yu said.
Essentially, the same goes for light rail trains. Yu said ATSAC engineers have created several systems for trains within the system itself. He said that was the case for the Expo Line, which went online on Saturday.
“We’ve been testing [the Expo Line],” Yu said. “It’s being tested right now.”
He said the ATSAC system can also be a resource for law enforcement as well; however, while officers are allowed to view it, they cannot alter it. Yu said the video is never recorded, and the data compiled is only available for one week.
“We share the image with them, but we have control over the image,” he said, adding that officials share information to improve safety. “We do work hand in hand with the police department.”
Yu said the center does not let Google access the system either. However, like Google, ATSAC engineers allow residents to use its system to view real-time traffic conditions through its website, trafficinfo.lacity.org.
Thanks to $150 million in Prop. B money, the ATSAC center is nearing completion. Though the center is expected to be completed by January, Yu said the system, all of which was created in-house, still features components from the ’84 Games that could use upgrades.
“The system may be done, but our job is never done,” he said. “It’s a very delicate system. There’s no other city in the world that can do what we do here.”