Updated April 24, 2018 at 6:15 am: The axis title on the headway history chart at the end of this article has been corrected from “Minutes” to “Seconds” to reflect the units by which headways are stated in the chart.

In Part I, I reviewed the travel times for buses and streetcars on 506 Carlton since September 2017. In Part II, I will turn to headway reliability – the degree to which service actually operates with evenly spaced vehicles – as well as the capacity of service provided. A followup section looks back to September 2015 to compare operations over a longer timespan.

When the TTC reports on service quality, they have a very limited target: that vehicles leave their terminals no more than 1 minute early or 5 minutes late. Performance stats at the route level have not been published for three years, although there are plans to resume this practice soon. However, there are problems with summarizing data at the level the TTC reports:

• Results are consolidated for entire days and months so that variations are smoothed out, and the raggedness both in hour-to-hour and day-to-day performance is hidden.
• Relatively poor performance in peak periods can be masked in averages by better performance in the off-peak. Even though there are fewer off-peak vehicles, there are more off-peak hours and hence more trips.
• There is no measure of service quality except at terminals even though that is not where most riders use the service.
• The absence of mid-route measurements means that there is no penalty in a missed “target” for line management quality over the length of a route.
• The six-minute window (+1 to -5) allows pairs of vehicles on routes with short headways to depart from terminals while still being considered “on time”.
• Route capacity is wasted because some vehicles run half-empty close behind their leaders, and the average rider experience is that vehicles are infrequent and crowded. The TTC has no metric to identify and monitor this problem.

Service on 506 Carlton has been erratic for many years and the shift to bus operation in February 2018 has not improved route performance. Although buses are scheduled closer together for capacity reasons, headways remain erratic and in some cases the variation in headways has widened since the move to bus operation.

Looking at these charts, it is a wonder that anybody tries to ride this line at all. It is a textbook example of providing bad and slowly declining service on what was once a trunk route in the system. As density builds up along the “shoulder downtown”, routes like Carlton have an important role, if only the TTC would make the effort to provide more attractive service.

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