In the first part of this review, I extended previous charts showing travel times through the Jarvis-Bathurst “pilot” area to the end of March 2019. This installment turns to the question of headway reliability – how regularly do streetcars arrive – as opposed to how long they require to cross the pilot district. A rider’s experience is affected by both of these factors, not to mention the basic question of “can I get on” when a streetcar does show up.
Although one end of a journey might be within the pilot, many trips on the King car begin or end beyond the pilot’s limits. They are affected by service quality along the whole route, not just in the core. This article begins by looking at March 2019 service at Yonge Street, and then moves further afield including the termini of the route.
The weather varied considerably over March 2019, but this did not play a big factor in the data overall, and statistics for most weeks and locations are similar. The larger issue is that service at the terminals is irregular most of the time, and this makes it impossible to have a properly “blended” service in the central part of the route.
The measurement shown in this article are taken at various screenlines along the route.
- Southbound on Broadview crossing Danforth (leaving Broadview Station)
- Northbound on Cherry crossing Mill (leaving Distillery Loop)
- Westbound on King crossing Parliament (blended service from 504A/B). Note that any short turns coming south on Parliament are not included.
- Westbound on King crossing Yonge
- Southbound on Dundas crossing Bloor (leaving Dundas West Station)
- Northbound on Dufferin crossing Springhurst (leaving Dufferin Loop)
- Eastbound on King crossing Strachan (blended service)
- Eastbound on King crossing Yonge
Headway Reliability at Yonge
The service at Yonge Street includes both the 504A and 504B branches of the King route. Their schedules normally have the same headway and so in theory this should be a blended service of cars alternating between destinations on a combined headway half that of each branch.
There are various ways of presenting the headway data each of which reveals a different aspect of the operation.
Headway Scatter Chart
Each dot on the chart represents one car with different colours for each day. The horizontal position is the time of day, and the vertical position is the headway in front of the car when it crossed Yonge Street. Note that because of the farside stop, few values are right at the zero line because cars tend to wait their turn and do not cross within the same 20-second interval used by the vehicle tracking system.
The wavy coloured lines are best fit curves threaded through the data to show how the values behave over the course of the day. Note that even though the dots for each day may be in different locations, the overall values as shown by the trend lines is quite similar for each day. In other words, one day is very much like another.
The scheduled combined headways of the King branches in March were:
- 2’38” in the AM peak
- 3’30” in the midday
- 3’00” in the PM peak
- 3’15” in the early evening
- 4’30” in the late evening
The trend lines lie generally on the scheduled values as one would expect at the middle of the route where there should be no effects from short turns and all service is present.
The full Service Summary for 504 King is shown below.
Averages and Deviations
Another way to look at the same data is to see the hourly averages and standard deviations (a measure of how dispersed the values are around the average).
On this chart, each week’s data is displayed in a different colour (the red line corresponds to the week 1 data on the previous chart). The solid line shows the hourly average values and the dotted lines show the standard deviations. The latter values are of some concern because they lie close to the averages. This indicates that the band of data values around the averages for over half of the headways is close to the scheduled headway itself. In other words, many cars are running two headways apart, and by implication others are running very close together. This is evident in the scatter diagram, but the chart of averages and SDs shows that this is a consistent pattern for all weeks in the month.
Note that “week 1” actually is six days long because March 1 is a Friday and is included with the following week.
The chart below shows the week 1 data in “block and whisker” format breaking down the range for each of four quartiles.
Each column displays the data for one hour within week 1. The green and blue boxes show the range of the second and third quartiles with the dividing line being the median value for the data. The red “whiskers” at the bottom show the range of the first quartile data, while the upper purple whiskers show the fourth quartile.
This chart shows that one quarter of the service operates well below the median headway, close to zero, and another quarter operates well above reaching values of 10 minutes and more throughout the day. The other half of the service lies within the green and blue boxes. The shorter this box is, the closer to the scheduled headway half of the service is operating, but the “whiskers” ideally should not be so long.
This is a simplified view of the scatter chart above. From a rider’s point of view, wait times are important and more people will accumulate at a stop during a wide headway than a narrow one. More riders “see” the gaps (and following bunches) even though the average and median headways might be close to the scheduled values. This also affects crowding on cars.
Weekends show little difference. The Saturday data are shown below, and the Sunday data are quite similar except for the early morning hours.
All of the charts above are for westbound service. The eastbound charts are quite similar. Full sets for both directions are available below.
A classic argument about transit service is that bunching is inevitable given the vagaries of traffic and the impossibility of running precisely to a schedule. By the time the service reaches Yonge in either direction, what might have been a well-behaved service has fallen apart. At least that’s the story. However, when we look further away, this is not born out by the data.
Eastbound at Strachan Avenue
Service eastbound at Strachan is a mixture of the 504A cars originating from Dundas West Station and 504B cars from Dufferin Loop, with the services merging at King & Dufferin.
The data scatter at Strachan is similar to that at Yonge showing that service is already bunched before it reaches the core, and that this is a day-to-day situation.
Consistently through all weeks and all times of the day, the standard deviation values are close to the average values. When this occurs, cars are often running in pairs.
The hourly breakdown for week 1 at Strachan shows the familiar pattern with the first quartile reaching down almost to the zero value, and the fourth quartile regularly cresting the 10 minute line. Half of the service lies in the middle quartiles over a range of headways that sometimes breaks the TTC’s six-minute target, but half lies beyond above and below.
The full set of charts for Strachan EB is linked here:
Westbound at Parliament
Service westbound at Parliament is a mixture of 504B cars originating at Broadview Station and 504A cars from Distillery Loop with the services merging a few blocks to the east at Sumach & King Streets. The situation here is quite similar to that at Strachan Avenue even though this is close to the point where “blended” service merge. Many headways are close to zero and many range up to 10 minutes.
The weekly breakdown shows that this pattern is common across all weeks and time periods.
As at Strachan, the quartile chart below shows clearly that half of the service is operating on very short or long headways, effectively as bunches, inbound before the service reaches the pilot district.
The full set of charts for Parliament WB is linked here. Note that on Sunday, March 17 all streetcars diverted due to a collision that blocked service for the entire day on King east of Parliament. Only the occasional shuttle bus shows up in the stats for that day.
Service From the Terminals
Service at the terminals does not come close to meeting TTC standards with headways swinging wildly about the scheduled values and a lot of service running close together. The situation is physically complicated at Broadview and Dundas West Stations where there are routinely queues of streetcars waiting to enter while cars take layovers because they are early.
Conversely, short turns of service destined for Dufferin Loop, and to a lesser extent Distillery Loop, imply that cars are late and will not be able to make their scheduled trips. When the May data are available, we will see whether the planned expansion of recovery time on both 504 King branches will fix this or will merely contribute to terminal queues and even longer layovers.
With the service from the four terminals consistently so irregular, it is no wonder that the “blending” of services cannot occur properly. On top of this, there is no evidence of any effort to space cars where the branches merge, challenging though this would be with erratic service arriving on each branch.
During much of the day, the standard deviation values range from 4 to 6 minutes indicating that many trips are operating at a range of headways twice this wide. The pattern is consistent through all four weeks.
The range of headways covered by the second and third quartiles is routinely wider than 6 minutes, and the first and fourth quartiles extend considerably above and below.
The full set of charts is linked below. Note that there was no service to Broadview Station on the weekend of March 9/10 due to emergency track repairs at Riverdale Park.
As at Broadview Station there is a considerable scatter in the headways operated at Distillery Loop. On some days, short turning after the morning peak pulls the trend line higher. This occurred in weeks 1 and 3 as is shown in the weekly statistics chart. Short and very long headways are not unusual at Distillery Loop.
The following chart shows data for all weekdays and with the vertical scale set at 60 rather than 30 as in the other charts. The purpose is to show the cases where a headway value over half an hour was recorded. These show up in the “block and whisker” format charts as hours with fourth quartiles that run beyond the 30 minute upper range of the chart.
The week-by-week breakdown shows that the average headways stayed generally the same with a few exceptions, but that the standard deviations bounced over a range from about 3 to 8 minutes showing a wide variation in headways.
Looked at in quartile format, week 1 has several hours where the middle quartiles cover a fairly small range of values (e.g. 11 am), but the first and fourth do not. In particular, extremely short headways were common for much of the day especially in the late afternoon and evening.
Dundas West Station
The situation at the west end of 504 King is similar to that in the east with a wide range of headways for service departing from Dundas West Station.
The weekly statistics follow a similar pattern showing that this is common through the month.
Similarly the quartiles show that half of the service (first and fourth quartiles) operate on very short or very long headways well beyond the target range for TTC service.
Service from Dufferin Loop can be quite irregular as the chart below shows. Short turns in the late morning cause wider headways leaving the loop after the AM peak and this shows up in the trend lines below.
In the weekly breakdown, the post-AM peak effect is visible together with very high standard deviations showing that even with wide headways, there are bunches where two cars are carrying a gap.
As at the Distillery Loop, the first and fourth quartiles regularly reach down close to the zero line and well above 20 minutes, cresting the half hour mark on occasion.