City traffic control monitors movements of thousands of vehicles per day

Control centre relies on camera feeds, automated software to improve traffic flow

Inside a control room, located in a nondescript East York office building, a small team watches the city’s traffic unfold.

The group of traffic watchers, called operators, monitors feeds from dozens of cameras posted at the city’s busiest intersections, logging major traffic incidents 24/7. The team also coordinates emergency road closures, dispatches maintenance crews and communicates advisories to the commuting public.

On a gloomy October morning, traffic surprisingly moves well during the heart of rush hour. But even during this unusually calm period, the traffic control team logs 12 major incidents between 7 and 10 a.m., which is normally one of the busiest parts of the day, according to head controller Linda Lee.

“That’s just part of living in a city that’s booming,” said Lee Thursday, Oct. 20, during a tour of the traffic control centre. “When we look at our downtown cameras, it’s not just automobiles but lots of cyclists and pedestrians.”

Cameras capture traffic at expected hotspots like the Gardiner Expressway and the Don Valley Parkway. Feeds are also centred on Allen Road, Eglinton Avenue – more than 190 in all, capturing action in real-time.

The operators, contractors to the city, not only monitor traffic but also learn how to dispatch service. They undergo three months of training, learning how to operate the cameras, and familiarizing themselves with various locations. Each feed can be accessed by punching a four-digit code. Feeds starting with ‘8’, for example, reference expressway locations.

“It used to be we could ask an operator to bring up a (feed) and it was simple, but it’s a little more difficult because we’ve got so many cameras now,” she said. “Now it’s hard to remember them all.”

From the control room, operators can also make traffic signal-timing changes to improve flow. The process can also be automated, with the system making predictive changes based on detectors measuring the level of traffic. Operators can also favour traffic signals at certain routes at the expense of others to even out traffic flow. Over 300 current signals have the adaptive technology, according to Lee, with more to come.

The city has also undertaken re-timing its traffic signals, something which started back in 2012. Lee says a review has been undertaken of signal times at major arterials to improve the timing of traffic off-sets, so that there’s minimal wait-times between a succession of signals. All of the city’s 2,300 signals are scheduled for re-timing, with 939 completed at major routes. But re-timing is expensive, with one installation costing as much as $160,000 and regular maintenance $15,000 a year.

Lee admits it’s hard to explain to the public why some traffic lights take forever to turn green while others turn much faster.

“There are a lot of factors which can impact signal coordination,” she said.

A major intersection with multiple left-turn lanes, for example, will drive up the amount of time before the light changes. And for the signals to be coordinated, they all have to have the same “cycle length”. The spacing between lights is another factor, not to mention whether there are transit signals for TTC vehicles on the route. Sometimes, the detectors can be damaged through construction, causing the traffic signals to cycle without any apparent rhyme or reason.

The team monitors the communications of the traffic signals and dispatches a maintenance crew in case anything is off. In some cases there is daily monitoring, but in less busy areas that drops to weekly.

Lee says the value of the program comes from being able to easily coordinate a response to an incident. For example a disabled vehicle creating a massive traffic pileup can be more quickly diffused and authorities dispatched if it appears on a camera feed. Lee also gets tips from police, sometimes even media outlets advising of a traffic scenario.

The control centre also tracks response times and reviews with the pertinent authorities how to improve them. Analysis of traffic patterns also takes place, although Lee admits without the proper software, it’s not possible for a deep-dive into the information just yet. She’s hopeful new software ordered for the control centre will be able to provide automated suggestions to deal with a specific incident.

“Right now if an incident happens, our operators need to find the camera feed and then determine if messages have to be changed on an electronic road sign,” she said. “The advanced system on the way will provide suggestions on what to post and where to post it based on where the closure. It makes the process more efficient.”

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Source: InsideToronto