The Gradual Slowing of 512 St. Clair (Part III) (Updated)

This article is rather technical and is intended as an exploration of an alternate way of presenting dwell time statistics for routes to quickly identify where vehicles spend a lot of time, and in particular where there are extra stops near and farside of intersections.

Anyone who is interested in this discussion, please leave comments. The data presented here appeared in Part II of this series, but in a different format. This is an attempt to improve on the presentation.

Updated March 15, 2021 at 9:25 am: Charts have been added for 505 Dundas for weekdays and Saturdays in February 2021 as an illustration of the very different stopping behaviour on a mixed traffic route where all stops are nearside.

Updated March 14, 2021 at 9:00 pm: A sample chart has been added at the end of the article including a few changes in format.

Updated March 14, 2021 at 1:00 pm: The westbound charts originally published here were the wrong set and covered the period January 12-23 which includes two Sundays and excludes Fridays. The eastbound charts are for January 20-31 which includes only weekdays. All westbound charts and downloadable files have been replaced with new versions. The primary change is that replacing Sundays with Fridays increases the number of observations and strengthens the effects seen in peak periods.

I have received a request for raw data files so that people can play with their own versions. WordPress does not allow uploads of files that potentially could include executable code, macros, etc. If you want the data, please leave a comment and include a real email address.

Background on the Methodology

There is a challenge in figuring out where streetcars and buses spend their time because the vehicle tracking system does not record their location constantly, but rather on a routine update cycle. With the TTC’s new “Vision” system, this cycle is much shorter, but the vast majority of historical data I have comes from the pre-Vision system known as “CIS”, notably the streetcar network where full conversion did not complete until late 2020.

In the CIS system, the “polling interval” (the time between recorded locations of vehicles) is typically 20 seconds, although there can be cases where vehicles are missed. The most common problem lies with GPS signal reflections in certain parts of the city that caused cars to mis-report their location. Such data points must be discarded to avoid bizarre results in calculations of vehicle behaviour.

For consistency, where I do have either a mix of CIS and Vision data for a route (i.e. during the transition period) or all-Vision data, I round times in the observations to the same 20-second cycle as CIS data to allow analysis of all vehicles and time periods on a comparable basis. (Changing to a more fine-grained timescale is a project for another day, and I suspect it will not make much difference in the results.)

The starting point with any route’s data is that I “see” vehicles every 20 seconds. They might be stationary or they might be in motion.

A related part of the methodology I developed for this work is that the route geometry is converted into a one-dimensional space, in effect thinking of the line on the route map as a piece of string and pulling it out straight. One end of the string is the “zero” point, and there is a knot every 10m westward or northward dividing the route into small chunks independently of its twists and turns.

Why these directions? In TTC schedule parlance, westward or northward travel is usually “Up” while the reverse is “Down”. That’s what the “U” and “D” on transfers means.

GPS locations are mapped into this co-ordinate system by which every position on a route becomes a single number representing the distance from the eastern or southern terminus. There are special cases and challenges on a few routes, but in general this greatly simplifies and standardizes the internal representation of all routes. (The process is described in more detail in this article.)

For each “tick” of the clock, a vehicle is somewhere along this line, but when it is in motion, we rarely get two observations from adjacent points because vehicles travel more than 10m in 20 seconds. However, locations where vehicles are likely to be stopped will accumulate more vehicle observations than vehicles where they are usually moving. If you took a picture at any location every 20 seconds, some photos would have a bus or streetcar, but many would not.

To determine how likely it might be for a bus or streetcar to be delayed somewhere, it is not enough to just count how many observations there were in, say, an hour at each point along a route, although that will certainly show “popular” locations in the data. Of particular interest is the length of time vehicles spend without moving.

Even if a vehicle stops briefly to serve riders, it is possible that it will come and go within one 20 second cycle, although 40 (two cycles) is also likely. At busy stops, and particularly at stops where vehicles are held by traffic signals, left turns or congestion, a vehicle might appear within the same 10m segment of a route for over a minute.

(As an aside, the same sort of sampling is used to produce the average speed charts such as those in Part I of the series. Each observation is 20 seconds apart, and it is some multiple of 10m away from the next one. This makes calculating speed at that time simple, and values for many vehicles can be averaged to produce a speed profile for a route.)

For most analyses, I prefer to use about two weeks’ worth of data, subdivided by hour of the day, to avoid skewing from small numbers of unusual events. Using hourly periods gives data that are credible representatives of real conditions rather than smoothed over a long period. Averaging service at 10pm together with the peak hour would produce results that represent neither interval, and would mask behaviour specific to each of them.

This is probably the single biggest problem with many of the stats presented by the TTC: they are averaged over very long periods and a large number of observations during wildly different operating conditions. This is rather like saying that, on average, the DVP is not congested.

Looking at St. Clair

The charts below show the dwell time profile for 512 St. Clair westbound in the PM peak hour. The data are from the last two weeks of January 2020, pre-pandemic, and without any major winter storms.

To avoid crowding, the route is broken into two overlapping segments. Note that the horizontal scale is not exactly the same because the western “half” is slightly longer than the eastern one, but this does not affect what the charts display.

Each colour on the chart represents the group of cars that were observed for varying intervals at each 10m increment along the route. Green is for a single observation (i.e. one 20 second “tick” of the clock), while orange is for two (40 seconds) and so on up to dark red for six or more (2 minutes or above). There will always be more observations where cars are driving slowly, or are stopped briefly, but cases where they stay longer stick out quite clearly.

The basic point is that if a spike is not green, this is a location of interest. Mostly these are nearside or farside stop locations. If the predominant colour shows an even longer dwell for many of the vehicles, then this is could be a location with real problems unless there is a mitigating factor such as being at a terminal or subway interchange. In particular, longer dwells nearside of an intersection where the stop is farside show that traffic signals are not working in transit’s favour.

Several points to note here:

  • Travel westbound is from left to right across the charts.
  • Because cars loop through St. Clair West Station, they actually occupy the same 10m route segments more than once, and this causes particularly high counts at this location.
  • The pattern of double-stopping, once nearside and once farside, at stops is quite clear.
  • Bathurst Street is a point where streetcars are held for long periods.
  • Oakwood Avenue is consistently a location where cars remain for extended periods during almost all hours of the day.
  • At Gunns Loop, all of the dwell times are high because this is a layover point.

Click on any chart to see a larger version.

Here are the corresponding charts for eastbound travel. The direction of travel is right-to-left.

Here are the westbound charts for the 8-9am peak hour.

Here are the eastbound charts for 8-9am.

Below are links to full chart sets with one page for each hour. You can step through these as flip-chart animation to see how the stats evolve through the day. Problem locations rise and fall in the peaks and off-peaks.


These charts are a work in progress, but I would like to settle the format before turning to other routes with rights-of-way and farside stops.

In the process of writing this, I have already seen a few things to change:

  • The “Stops” item in the legend is left over from another chart format and it should be removed.
  • The colours for the various intervals should be rearranged so that the progression is clearly from “cool” to “hot” for longer dwell times.
  • The two shades of red for “100” and “120” are too similar.
  • The “120 sec” legend should be changed to “120+” in recognition that this group contains all observations at or above a 2 minute dwell.

Please let me know via comments if these charts “work” in displaying a route’s stopping behaviour and if you have any ideas for ways to improve them. Thanks in advance.

Revised Version

Here is one of the charts with two formatting changes:

  • The 120 second data are now shown in a pink rather than dark red for better contrast with the 100 second red plot.
  • Vertical lines showing stop locations have been restored. (It was an Excel thing. Don’t ask.)

505 Dundas February 2021

As a contrast to the St. Clair data above, here are sets of charts for 505 Dundas for weekdays and Saturdays in February 2021. Among points worth noting:

  • There are locations where cars hold for extended periods that are not stops such as Victoria Street and south of Broadview Station.
  • Some stops have long dwell times such as Parliament eastbound on Saturday evenings. It appears that this (among other locations on the route) may be places where cars are held for time, possibly to minimize backups at Broadview Station.

15 thoughts on “The Gradual Slowing of 512 St. Clair (Part III) (Updated)

  1. Track vehicles or track users?

    While the TTC data is getting better which enables your analysis of it is uncovering ways to improve it, the TTC needs to become customer centric by tracking what the user experiences instead of just managing vehicle movement. In addition to your detailed insights have a look at what Google Maps provides for users trying to get from St Clair station to Christie/St Clair. The variations of travel time are huge. A person leaving at 9:11 will take 13 minutes, whereas if they take the next streetcar it’s 22 minutes. Additionally Google (using their mobile phone movement data) proposes the quickest options include getting off the streetcar and walking depending on your departure time. Another insight that could be added to the user view is the ratio between the trip time TTC vs car but the most important feature that comes from the user centric view is trip time when it includes multiple TTC routes/vehicles/transfers.

    In the end, its both, tracking users and vehicles but the TTC has to adopt the user centric view first to make the most of the resources they have. Sadly it seems Google knows the performance of the TTC better than the TTC does.

    Steve: Google uses the TTC’s published schedules, not actual travel times. At around 9 am there is a transition between early morning and regular service, and a change (longer) in scheduled trip times. Also for reasons I cannot fathom, there are some trips where Google adds walking time at one or both ends of the trip, and other trips are just the transit travel time. You still get on and off at the same stop. That’s where the variations you are seeing come from.

    For real world data, yes, my own tracking does show both travel time changes and wait times due to irregular service, and I have written about this many times. The TTC has such a fetish for “on time departure” at terminals as a single metric (there has to be a warehouse full of gold stars just to keep Rick Leary happy) that it ignores the factors that real riders see. I certainly agree with you on that. They keep claiming to be focused on customers, but that is always subject to (a) budgets and (b) making sure that the stats look good for management. Massing stats, of course, hides problems, but allows them to claim that the service is good. This has been going on for years at the TTC.


  2. Re 512 Street Car Route.

    I have never figured out why street cars, as well as buses serving this route, do not get the priority at the intersections where there is a left-hand advanced green for vehicles. Perhaps you can explain it to me? And you’re correct, the waiting time for U and D direction at Bathurst and St Clair W can be incredibly long, especially if there is more than one TTC vehicle behind each other, which does happen!

    Steve: Because the City’s transportation engineers are more worried about creating a backlog of turning traffic than in moving transit vehicles. There is a long history of “war on the car” political rhetoric in Toronto, coupled with the whole “St. Clair Disaster” meme. In Toronto “Transit Priority” means giving more time to transit vehicles if there is any left over. Commonly at major intersections there is no priority given at all because, perish the thought, east-west priority on St. Clair might delay traffic on north-south cross-streets.

    With the transition from David Miller to Rob Ford as mayor, many policies that would have favoured transit were reversed, and there has been no impetus from Council or the Mayor for real improvements ever since.


  3. To improve the charts, perhaps you could add vertical gridlines at the actual location for each stop. Just the label doesn’t make it clear.

    Steve: I have been fighting with Excel to do this. That’s what the “Stops” legend is all about. It will display the lines for a line graph, but not for an area chart. Combo format charts have some strange behaviours.


  4. Two ideas which may not be useful.

    1. Filter out all the 20-seconds-only readings?

    Steve: It’s easy to omit the 20-second readings by switching off that series in the chart. However this masks the relative proportion of the larger values in the total. In due course, I wil add some samples of suggested modified charts to the article.

    2. A pie chart for small segments of route showing proportion of vehicles in that section in each time reading.

    Steve: I am not quite sure what you mean by this. How “wide” is a “small segment”?


  5. I remember the 1950’s and 1960’s, when the PCC streetcar trains would be loading up on the nearside of intersections. They would close the doors, and if they had a YELLOW light, they would start into the intersection, and even if the cross street gets their green the second streetcar in the two-car train would roll on through the intersection. Of course, being a “street railway”, it was assumed by us that the streetcars had the priority.

    In the 1950’s and 1960’s, streetcar and subway operators did not have to have a MTO driver’s license. Only if they drove the buses. Today, they have to “follow the rules of the road”, including the traffic signals, which were originally designed for motor vehicles.

    Steve: Buses drivers still do this quite routinely, and it’s something of a double standard within the TTC that they get away with it. One reason riders say buses are so much better than streetcars during replacements is that the buses drive as if they are on suburban streets. If a streetcar operator tried the same thing, they would be “disciplined”. There is also the permanent slow order on any special work, and the fact that the electric switch electronics have not worked basically for three decades and are only now, slowly, being upgraded. Imagine this sort of approach to subway maintenance. Oh wait, we’ve been down that road in the 90s.

    A long-retired operator I knew called this “a blushing amber”. Particularly with the new larger cars and the TTC’s focus on safe operation they are much less willing to pull away from a stop at the end of a signal cycle. After all, the “transit priority” is supposed to extend their green time. Don’t get me started.


  6. Thanks for the reply notes. Masking the relative size by turning off the green is a good point.

    I’ve rethought my pie chart scheme and it would mask too much, and not be useful. Perhaps it came before enough coffee this morning!


  7. I apologize first because I haven’t fully read the methodology. I was looking at the graphs and Thing1’s comment of a segment of a route. I started with east end westbound evening and saw the spikes from Bathurst to Christie. I didn’t expect the symmetry for eastbound.

    So I switched to the morning.

    I’m sorry if I’m now off topic, but the cumulative delay in this stretch for the worst street car trip may be very frustrating. The delays are in both directions both morning and evening. If the TTC and City street work to co-ordinate may a significant throughput gain could be achieved?

    I put all four graphs together, it summarizes my way of looking at it, but may not be informative.

    Will stop looking at the pictures and will read the hard stuff now.

    Steve: Yes there is a lot of symmetry in the eastbound and westbound charts with a few examples related to different conditions at specific locations. There is a subtle difference between directions in locations of spikes on either side of the intersection. The front of a car at the stop bar nearside is over 30m away from the front of an adjacent car travelling the opposite direction and stopped farside.

    The Bathurst-Vaughan area is a big problem, especially because a car stopped farside completely blocks an island whereas when CLRVs operated, two cars could serve an island at the same time. Even though St. Clair was designed for 30m cars, I don’t think anyone considered the dynamics of how a one-car-length island would actually work at busy locations.


  8. Steve said: I don’t think anyone considered the dynamics of how a one-car-length island would actually work at busy locations.

    I simply used the pictures Steve provided and jumped to the conclusion that Bathurst to Christie was a problem, without fully understanding the problem. It seems that there is a real problem. I’m sure simulations of this area would have identified this problem and would have told us that spending the millions would not be of great benefit.

    The simulations have showed that spending the $6 billion on the Scarborough Subway Extension will provide 103,000 daily trips and $1.6 billion on SmartTrack will produce 35,000 daily trips. We don’t have to spend the billions to find out we will be unhappy with the result.

    Both the Provincial and Municipal elected officials are wasting our tax money. Government has to work for the people.


  9. “The simulations have showed that spending the $6 billion on the Scarborough Subway Extension will provide 103,000 daily trips and $1.6 billion on SmartTrack will produce 35,000 daily trips.”

    Spending $0.003 billion on the King Street Project resulted in a 17% increase in streetcar ridership to 84,000 daily trips. Source

    Perhaps the most efficient use of tax money is to extend this treatment to other streetcar routes. And improve the King Street Project with barriers to keep private automobiles out.

    Liked by 1 person

  10. I was very pleased when I first heard that the St Clair Streetcar was to be restored to the private right of way that was pulled out from under it during the Depression to facilitate the auto heaven we now possess.

    Then came the construction mess which bankrupted more than a few businesses that were unlucky enough to have been located on St Clair. But, of course, I knew that it would all work out in the end, and those dumb Fordites would get an education.

    Well, I’m the one with a PhD in TTC/political folly. Given the comments in all three sections, plus Steve’s original stats; the whole St Clair PROW has been an expensive, dislocating, flop!

    It didn’t have to be that way, of course, but Toronto’s leaders have zero constructive will, and the TTC seems to feel that it’s dealing with a union that emigrated from Liverpool in the seventies.

    Steve: I would not say that St. Clair is a flop, and there is always the question of how much worse conditions would have become if the right-of-way were not there. That said, there were basic issues in the design and operation that show we are not getting as much benefit as we could out of the right-of-way. The construction project was not as well managed as it might have been leading to extended upheavals for neighbourhoods.

    Your comment about “dealing with a union” is completely out of place and has nothing to do with the St. Clair project’s construction and design. If you are referring to operations, yes, there are issues that the service is not managed as well as it could be, but management must take responsibility for concocting metrics of “good service” that bear little relationship to what riders actually experience. It is very hard to correct problems when the monitoring system is organized to hide them. There are supposed to be new metrics revealed in April, and we will see whether they also bring a change in service planning and management rather than being new threads for the emperor.


  11. It was TTC management’s apparent perception of labour ‘issues’ that I referred to, not the union itself.


  12. I live in Scarborough (bus user) and didn’t understand the issue. I have now looked at a Google map and was surprised to learn that the “hot spots” are not street car stops but traffic conditions. The road intersections are irregular. It appears to me, to be a capacity issue, there is not enough room for cars and streetcars to run smoothly.

    Again, from someone from Scarborough, the west of Yonge city transit problems are old European city issues trying to adapt to cars. The only east west roads I know are Eglinton and St. Clair. An east west road built with an overpass over the Cedarvale ravine would have addressed the congestion but such is life. The Dufferin Bathurst corridor is another capacity limiting issue.

    To an outsider, there isn’t enough surface space for cars and public transit, yet developers are increasing density.

    Steve hates off-the wall ideas, but Mumbai has built plenty of elevated monorail trains. Time to face the music, there is not enough road space for cars and public transit.
    Only an opinion, I don’t know the facts.


  13. Re: Steve’s comments about a backlog of turning vehicles on St. Clair — this is actually a major issue at the Vaughan-St Clair-Bathurst interchange, where there is high demand for eastbound St Clair car traffic to turn northbound onto Bathurst — to the extent that eastbound through traffic is frequently backed up well west of Vaughan Road.

    The configuration there is messed up — too much street parking, traffic light cycles are off, two streetcar stops 100 m apart. The city needs to get creative there.

    A related situation obtains at Winona-St Clair-Alberta where there are backups (for cars and streetcars) seemingly at all hours.


  14. Jordan said: The city needs to get creative there.

    Jordan’s explanations in his post helped me the most, to understand the situation.

    When he says “The city needs to get creative”, it is my experience that this is City staff’s biggest weakness. I have yet to meet any city staff willing to tackle these kind of problems. As far as I know there is a “Roads Department” that is responsible. I only have experience with the Scarborough group who explained to me that they look at things when called upon and the things I was interested in have never been called upon. If the “Roads Department” has been called upon to straighten out the congestion at Vaughan-St Clair-Bathurst, we see the results of their work.

    I am just learning how the City works, and it seems to me, this is neither a City Planning nor TTC issue. Are there any 311 experts who knows who should be dealing with this problem?


  15. I live near St Clair W & Bathurst. As another commentor suggested, that intersection and St Clair & Vaughan don’t work for anyone. It’s a good example of Toronto’s addiction to on-street parking. Traffic eastbound on SCW can back up to Wychwood during peak hours, all so three people can park smack in front of the Shopper’s.

    Beyond the issues they raised, I suspect part of the long dwell times is that the #90 Vaughan and #126 Christie share the 512 ROW right there. I have sat on the westbound 512 many times waiting on the buses ahead to clear the farside St Clair W/Bathurst stop (or on a bus waiting on the 512 to clear). Both buses leave the ROW at the light after Bathurst, so the problem is gone after Bathurst. If the platform at SCW/B was long enough to accommodate the common demand of 2 buses+streetcar or if all 3 routes didn’t leave the station simultaneously, this wouldn’t be so much of an issue.

    Liked by 1 person

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