The 903 Express bus replacing the former Scarborough Rapid Transit Line 3 began operating formally in September 2023 after the SRT shut down in July. Initially the route operated totally in mixed traffic, but red lanes were added to speed operation. Also, the route initially operated via Progress, but shifted to Ellesmere in mid-November after roadway changes to support the route.

Initial service was extremely frequent, but this was cut back in November 2023 when several other routes were extended south from STC to Kennedy Station to provide a one-seat ride to passengers who otherwise would have to transfer at STC station. The 903 Express remains in operation, but less frequently thanks to the presence of other services.

Although many routes now share the corridor south via Midland and north via Kennedy between Ellesmere and Kennedy Station, the 903 Express can stand in for all routes to measure travel times.

A few points revealed here:

• Service on this route is fairly regular with much less of the headway spread into gaps and bunches seen on other route analyses. This is likely due to the demand pattern with few stops, and less cumulative delay from boarding/alighting passengers along the route, combined with reliable departures at the terminals.
• Where buses are crowded, this usually shows up as a series of regularly spaced vehicles with heavy loads, not as single crowded buses after wide gaps.
• The benefit of the red lanes varies by location, direction and time of day. Travel times are included here as a reference point for future comparison when the SRT busway goes into service, as well as to track any spillover effects from Scarborough Subway construction.

Updated November 9, 2024 at 4:40pm: The operating chart including crowding status has been added for October 16 as a counterpart to the bus spacing charts for the same day.

Scheduled Service

Here are the scheduled service summaries for the 903 Express service as it was initially implemented in 2023 and in Fall 2024.

Note that the route is longer now than initially when it operated to STC, and the amount of terminal time in the schedule is now extremely large ranging from 15-26 minutes per round trip, sometimes over 50% of the allocated driving time.

Headway Reliability October 2024

A striking contrast here compared with other routes I have analyzed is that most of the headways (the spacing between buses) is concentrated in a narrow band all day long and in both directions. This set of charts shows northbound (left) and southbound (right) service by hour of the day consolidating stats from all weekdays in the month of October 2024 at screenlines along the route.

The central yellow-green block holds the second and third quartile of values (25-75th percentiles) and represents half of all trips. This band stays narrow at the trip origins (left side of each set of columns), and does not widen much along the route.

The horizontal bars on the upper and lower “tails” mark the 90th and 10th percentiles, and so 80% of the headways lie within these bounds. Ten percent are above the upper bar (wider gaps) and ten percent are under the lower one (bunching).

Crowding Levels October 2024

The next set of charts shows the crowding level. As with the headway charts above, each set of columns holds one hour’s data as observed at the screenlines. Crowding is concentrated in the peak periods.

Some intervals show a buildup of crowding along the route such as the 8am northbound data which indicates that demand builds up northbound from Kennedy Station to Centennial College at Markham Road. In the afternoon, the pattern is different with crowding showing some transfers on/off at Lawrence, but the main drop is at STC.

Southbound crowding occurs on a small scale in the AM peak, but in the afternoon shows well-loaded buses at the origin of the line at Centennial, some drop off at STC, and most of the rest at Kennedy Stn. Note that the period of heavy demand is spread out through the afternoon and early evening.

Vehicle Spacing Wednesday, October 16, 2024

As an example of the well-behaved spacing of buses on this route, here are charts of bus spacing for one day taken as a sample from mid-month. Because much of the demand boards at a few major stops, the effect seen on other routes with bunches forming behind gaps does not occur here through the cumulative effect of longer stop service times.

Operating Chart Showing Crowding For October 16, 2024

These charts show the movement of buses on October 16 corresponding to the spacing chart above. Note that where buses are crowded this is generally not associated with a gap in service showing that the crowding is simply a matter of the demand level at that location, direction and time.

There is a “wiggle” in most of the downward traces for southbound buses. This is due to two factors:

• Southbound buses make the left turn from Ellesmere to Midland by driving west to Ellesmere Station, circling that loop, and returning east to Midland. This produces the sawtooth in the tracking chart.
• The southbound route via Midland is shorter than northbound via Kennedy. To chart both directions on the same page, there is a “reset” to realign southbound trips with the grid based on the longer northbound route.

Travel Time Between STC and Kennedy Station

For the purpose of this analysis, I established three screenlines in my route model located at:

• The western end of the loop at Scarborough Centre Station (aka “STCWest”)
• The eastern approach to Kennedy Station just east of the SRT/GO corridor
• The western approach to Kennedy Station just west of the station access roadways

The purpose of these is to measure travel times without complications caused by buses looping around, and possibly laying over within, terminals. For southbound trips, the east screenline is used at Kennedy Station, and for northbound trips, the west screenline is used. This will not capture all of a rider’s travel time including terminal access at Kennedy and Scarborough Centre Stations, but it measures travel between the perimeters of the two stations.

(When the SRT busway opens, there will be a common Kennedy Station screenline at the south end of the busway replacing those on the eastern and western approaches.)

Here are charts of average travel times by hour on weekdays between Kennedy Station and STCWest in October 2024. The times are fairly even all day long, and the standard deviations are mostly small, within 1-2 minutes, indication that most trip times are close to the average value.

Here are the travel times showing 50th and 85th percentile values for four hourly periods through the day from September 2023 to October 2024.

Although the addition of red lanes early in the life of the 903 Express obviously reduced travel times, there is a question of which segment(s) benefits from this change. The following charts are organized by time of day, location and direction. Two of the segments illustrated gained red lanes (Kennedy Station to Lawrence, and Lawrence to Ellesmere), while the other (Ellesmere to STC West) only has red lanes for part of the distance.

The largest reduction in travel time is seen in the segment between Ellesmere and Lawrence. For some segments and time periods there is no change at all.

AM Peak

Midday

PM Peak

Early Evening