June 6, 2009
Doors Open Ottawa 2009 - Traffic Operations

Today was the first day of the seventh annual Doors Open Ottawa - a wonderful free event that we look forward to every year.  Last year we visited the Britannia Water Purification Plant and Canada Post. 


This year, we decided to go to the Traffic Operations building and find out more about the various cameras and computers installed at traffic lights around the city.  This was an excellent choice of event to do with Elizabeth - she loved all the bright lights everywhere.  She was particularly interested in the blinking lights on the servers upstairs!


The staff did a superb job, and those we interacted with were obviously proud of what they do.


There were fewer cameras than I had thought.  While more than a thousand traffic lights are connected back to the traffic operations centre, providing information about the colour of the light and whether they are working correctly, just over a hundred have cameras.  The cameras can rotate 360 degrees and are capable of zooming two kilometres in any direction.  I wish I could link to a video of this - it was quite something!  The guide pointed out that this means each camera can cover up to 15 intersections, depending on line of sight.  The data from each camera is stored for at least four weeks, and in some cases indefinitely.  We had noticed before that some of the video feeds are continuous and others are not.  This is because some cameras have fiber internet connections, and others are limited to GPRS.


The red light camera system is entirely separate - Traffic Operations takes the film out of the camera and sends it to the province for processing. It sounded very old fashioned compared to the state of the art stuff they are doing otherwise.  We were interested to hear about a pilot project running on two firetrucks in the city.  These have been equipped with a GPS signal capable of changing the lights to green in their direction.   I'm not sure why the project was limited to two trucks but it sounded like a great idea to me.  Hopefully their infrastructure is secure because that also sounds like technology that somebody might like to have in their own private vehicle.


Apparently all the software was written inhouse, with "some assistance from a few outside companies".  We were quite impressed with our glimpse of their server room through the glass.  They can control the timing of the lights and pedestrian signals with just a few keystrokes.  Representatives from OC Transpo and various emergency services will sometimes come and hang out.  For example, on a snow day they will look at the areas that are particularly congested and change their routes accordingly.  Apparently when President Obama came to visit there were 25 people on hand in the control room to observe traffic and make sure everything was going to plan.


All of the signage is produced on site, which I found quite surprising.  It's apparently cheaper.  We were surprised by how large the signs and traffic signals actually are - they seem smaller hanging high in the air or on the side of the road.  That is an oversize stop sign we're posing with though!  Oversize stop signs are about four times as large as the normal ones, and they are used at problem intersections, especially in rural areas.


Did you know that if you hold down the cross-walk button at any given intersection for about five seconds, it will chirp at you when it is safe to cross?  This is to help the visually impaired orient themselves without causing noise pollution at other times.  North and South intersections peep-peep, while East and West intersections coo-coo.  That's why the braille at pedestrian crosswalks read NPP, SPP, ECC and WCC (Brendan and I have wondered this for some time!).


We also learned that a pedestrian signal takes a 60 W bulb, while the larger stop lights (these are the ones that hang over an intersection) have a 135 W bulb.  The lens for a large stop light is 12 inches in diameter!  They really are quite a bit bigger than they look.  They are working to replace them with LED traffic lights but it sounded like this is a work in progress.


Signs are replaced more often if they are facing sunny south because they fade more quickly, and the average life span of a stop sign in Ottawa is about ten years.  They apparently test the reflectivity of the signs around the city on an ongoing basis to make sure they are working correctly.


The City of Ottawa employs seven people who are in charge of maintaining the mechanics of the lights.  Unfortunately I missed most of this presentation due to a diaper incident, but the one thing I heard: if you press the pedestrian button and it doesn't work, you should call the city (311) and they will dispatch one of these seven people within an hour.  Unsurprisingly, the washroom wasn't exactly equipped for easy diaper changes, but there was a locker-room area in the women's washroom with carpeted floor which meant that changing Elizabeth was actually easier than at the library (which hosts baby and toddler time once or twice a week...).


Another tour stop explained that pressing the pedestrian button multiple times really doesn't make the lights change any faster.  Nor does getting out of your car to push the button.   At least in Ottawa, the button and the metal detectors in the road (shown by those three yellow dots) trigger the same code.  During a given time period, only a small portion will actually trigger a light change.  So if you press the button or drive over the metal detector outside that time period, it won't do anything until it reaches the right part of its cycle. 


Another interesting thing we learned about metal detectors - some intersections have more than one.  In fact, the guy estimated that there were between five and six thousand installed around the city!  If there are multiple metal detectors, the second detector is installed in the middle of the road about eight car lengths back.  This detects whether there is a long line up of cars (or a bus), and the light is adjusted automatically to allow more cars to turn.


The last stop featured the line painting truck, which operates from April to November, employs thirty-five people working in round-the-clock shifts and paints 4.5 million meters a year!  The paint takes three minutes to dry.  In addition to people putting out and taking away cones there are actually multiple people on the truck responsible for driving, painting and putting gaps in the paint.  The truck is zooming along at 15 to 22km per hour, which doesn't sound fast unless you are the guy putting in the paint spaces...


All in all it was lots of fun and we're already looking forward to next year!

On June 12, 2009 at 10:20 pm
Mary said:
The traffic operations was also written about on the centretown blog in March - they have a few extra pictures and details.

Part I: http://centretown.blogspot.com/2009/03/traffic-operations-division-tour-part-i.html

Part II:


Part III:


On June 15, 2009 at 05:06 pm
Beth said:
This was really, really interesting! Thanks for writing it up.

On October 10, 2013 at 04:16 pm
Charles A-M said:
I was just re-reading my blog post and saw your comment. I guess I missed your link to this blog post at the time, or perhaps I was too busy to read it. I nevertheless learned a couple things from your writeup!

A couple comments: You can view the traffic cameras (including provincial ones) online on the City's Interactive Traffic Map: http://traffic.ottawa.ca/ (this probably wasn't available when you wrote your blog post)

Also, a nuance in your comment that getting out of your car is no different than getting out to press the button. The light will change at the same time either way, but if the vehicle loop is activated without a pedestrian button being pressed, the pedestrian signal won't activate (a big bone in many pedestrians' comments!)

I have a couple long blog posts about traffic signal loops (from a cycling perspective):


And about pedstrian buttons:



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