Saturday, March 21, 2009

Traffic Operations Division Tour, part I

[This is the first of a three-part series. Part II, Part III + epilogue.]

Last Monday, I had the opportunity of sitting in on a meeting of the City's Roads and Cycling Advisory Committee, a group of individual volunteers (mostly cyclists) who provide official input to the City on cycling issues. The City has other Advisory Committees, including RCAC's sibling committee, the Pedestrian and Transit Advisory Committee (which is chaired by CCCA President Shawn Menard), the Local Architecture Conservation Advisory Committee, the Poverty Issues Advisory Committee, the Business Advisory Committee, etc. These committees are an inexpensive and very valuable form of input to the City.

This particular meeting was special because it was held at the City's Traffic Operations Division building at 175 Loretta, off of Gladstone just past the O-Train tracks. I took lots of photos (and even a video) and will be dividing up the tour into three posts (which will be scheduled to post in three-day intervals.

Here's the outside of the building. The sign at the front still has the old Regional Municipality of Ottawa-Carleton (RMOC) logo. You can see the Queensway in the back.

This is the traffic control room. From here, they monitor the 96 traffic cameras around the City. (You can watch them too on the City's website here!) While the online cameras are pretty low resolution and only refresh every few seconds, the ones in the control room display like regular video. They've been monitoring traffic since 1976!

Those two screens at the bottom are a visual display of all the intersections in the City, which monitors each traffic signal once a second. At the back of the room was a large screen showing one of these displays. If you look carefully, number 112 has a red dot next to it, incidating a problem of some sort.

Along the back wall are monitors showing three of the MTO's traffic cameras along the 417.

Now here's the cool part. All 96 cameras can be remotely controlled with pan/tilt/zoom. Here, Omar is at the controls giving a look around the city.

I took a video of him zipping through the Bank/Somerset intersection. He can even see down to Kent! This gives a better idea of what it's like watching all these video monitors. And this is at 6pm--it must be really fun watching during the day!

There are three different levels of traffic systems that they use to control the signals: regular signal timing schedules based on yearly data, statistics and traffic patterns; 5000 sensor systems in the roads that modify the signal timing on a per-cycle basis based on current traffic contidions; and manual override by operators like Omar, above.

This chart shows the way the signals are organized. Many of them are synchronized, so that you can drive along of stretch of road and get green lights most of the way. The rest are free, which means that their cycles aren't dependent on other intersections. The implications of this is that on a free intersection, if you're on a cross street and press the pedestrian button, the light can change immediately. On a synchronized intersection, it has to wait until a specific part of the cycle before it changes. With time for pedestrian crossings, protected left turns, and through traffic, the minimum time for a cycle at an average intersection is about 80 seconds.

Here, Tom Fitzgerald, Superintendent of Traffic Operations, demonstrates how a signal loop triggers from the metal in a sledgehammer (representing the metal in a bicycle). Three yellow dots are placed on loops at intersections to indicate the place where the signal is strongest. When you put your bike over the yellow dots, it will detect your bike and change the light at the right part of the cycle. Some other jurisdictions use a small bicycle stencil to mark this function, which is more expensive. Others use red, yellow and green circles. (This photo is also a sneak-peek of the third post on signals)

The third level is manual intervention. At the back of the traffic control room is a row of computer stations where people monitor traffic and make interventions where necessary, such as changing the messages on overhead message boards (I think the closest one of these to Centretown is on the Bank Street bridge over the Canal heading toward Lansdowne Park). This room was full of people during Barack Obama's visit last month. You can also get a bit of a view of the server room through the glass door at the other end of the room.

Above the screen in the meeting room was the Department's Mission Statement plaque from pre-amalgamation: "We are dedicated to the delivery of transportation services that enhance the quality of life in Ottawa-Carleton."

And that's the end of Part I. Stay tuned for Part II: signs on Monday, and Part III: signals on Wednesday.

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