Stouffville line

Originally laid by the Toronto and Nipissing Railway, the track came into operation in 1871. The T&N merged with the Midland Railway of Canada in 1882. Only two years later, the Grand Trunk Railway leased most of the lines in the area as part of a major expansion plan and then purchased them outright in 1893. The Grand Trunk would later merge with the Canadian National Railway in 1923. CN would provide passenger rail service on the line until the formation of Via Rail in 1977.

On September 7, 1982, Via service was discontinued and replacement service—then just a single weekday run—was started by GO Transit.[6]

On June 29, 1998, GO Transit restored full service to the Lakeshore lines, and terminated Stouffville Line service to Danforth and Scarborough, which are shared with the Lakeshore East line.

On December 13, 2007, the government of Ontario announced funding to Metrolinx for network expansion, which included $20 million to build a second track to enable all-day two-way service between Union Station and Markham.[7]

On September 2, 2008, the line was extended northwards from Stouffville to Old Elm. Old Elm GO Station was built directly over GO Transit's Stouffville Yard, and so it consists of six tracks and platforms instead of the usual one or two.

On February 2, 2015, select trains began stopping at Danforth GO Station as part of a year-long pilot project to increase GO service within the City of Toronto.[8] As of June 2017, many peak-period trains continue to stop at Danforth station, and one daily train also stops at Scarborough station.[3] These extra stops were ended sometime before November 2021.[5]

All-day weekday service was introduced on June 24, 2017. Trains began operating from as early as 5 a.m. to as late as 11:45 p.m. with hourly service in both directions between Unionville and Union Station during the midday and evening. Service in the counter-peak direction continued to be operated by buses.[3]

On April 8, 2019, midday train trips were extended to Mount Joy station, and buses continued the rest of the trip from Mount Joy to Lincolnville.[9]

On August 31, 2019, GO Transit began providing bidirectional late-evening service between Union Station and Mount Joy, hourly between 9:30 p.m. and 11:30 p.m. The final northbound trip continues past Mount Joy and arrives at Lincolnville at 12:29 a.m.[10]

Starting on November 2, 2019, hourly two-way weekend train service between Mount Joy and Union Station began, with some morning and late night trips arriving in Lincolnville.[11]

From Union Station to Scarborough GO station, the Stouffville line's tracks are shared with the Kingston Subdivision and the Lakeshore East GO Transit corridor. The first station after Union Station, Danforth GO Station, is therefore shared with Lakeshore East trains. Stouffville line trains no longer serve Danforth and Scarborough stations. The Stouffville GO train switches to the Uxbridge Subdivision at Scarborough and begins curving towards the north until the Midland and Danforth Road intersection, at which point the line points straight north. The train then passes through residential neighborhoods up to Eglinton Avenue, and stops at the Kennedy GO station, which is the terminus for the TTC's Line 2, Line 3, and Line 5, upon opening.

As the train progresses through the route travelling adjacent to the Scarborough RT corridor in between Eglinton Avenue and Ellesmere Road, the train enters several industrial districts. Near the Kennedy GO Station area are several industrial spurs serviced during the overnight hours by the Canadian National Railway, the former Uxbridge Sub owner.[21] Continuing north, the train arrives at Agincourt GO station next, which is close to Sheppard Avenue.

North of Sheppard Avenue, the train passes through more residential and industrial areas. Just south of Steeles Avenue is the Milliken GO Station. Past Milliken, the train crosses Steeles Avenue and the site where the original Milliken station once stood, and enters the City of Markham, continuing north. Past Denison Street, the Stouffville train descends below 14th Avenue and the CN York Subdivision tracks before making its way back up, going beneath Highway 407 and stopping at Unionville GO Station.

Markham GO Station building

North of Unionville GO station, the train begins curving in the east direction, passing through historic Unionville (which includes the former Unionville Station building and platform) and residential suburban neighborhoods built closer to the track before arriving at Centennial GO station. Further along the line to the east is Markham GO station, which is located in the historic Markham Village.

After Markham GO station, the line curves northward again, passing industrial areas before approaching Mount Joy GO station, now a major terminal station for all non-peak trains. As the train departs from Mount Joy GO station, the scenery becomes much more rural as the line continues north, crossing 19th Avenue, exiting Markham, and entering the Town of Whitchurch-Stouffville.

Suburban development is seen once again as the train enters the historic village of Stouffville, stopping at Stouffville GO Station. Stouffville was once a major junction that connected the Uxbridge Sub with the Lake Simcoe Junction Railway.[22] Prior to 2020, passengers could see an abandoned track beside the main track where the trains were used to be stored. This track has since been removed.

The train continues until a little northeast, just exiting urban Stouffville, where it terminates at Old Elm GO Station, which is located next to the line's GO Train overnight storage facility.[23]

The Stouffville line operates nine trains out of Old Elm every weekday and three trains every weekend in either direction. Additional services dispatched from Union run as far north as Mount Joy GO, and connecting bus services extend north to Uxbridge. Train service is provided in push pull configuration with the MPI MP40PH-3C locomotive at the north end of the train and the Bombardier BiLevel cab control car at the south. The trains are typically six, ten, or twelve cars long, with the fifth car from the locomotive being the door control location.

Service levels have generally been adjusted several times a year with significant cutbacks during the COVID-19 pandemic. For a much of the year in 2022 until September, off-peak service was suspended to allow for construction.

As of September 2023, on regular service days (excluding weekends and holidays), the first southbound train departs Old Elm at 5:14 a.m. The rest of the trains follow at a service frequency of 30–60 minutes with most frequent service taking place during rush hour. The last southbound train departs Old Elm at 9:17 a.m. The first northbound train departs Union Station at 9:12 a.m. These mid-day trains turn back at Mount Joy, providing two-way service at 1 hour intervals until evening rush hour for the majority of stations on the line. North bound trains have a service frequency of 30–60 minutes with most frequent service taking place during rush hour. The last northbound train does not depart Union Station until 7:12 p.m.

As of November 2, 2019, the Stouffville line operated on all weekends and holidays with three trains departing hourly from Old Elm starting from 7:14 a.m. and three trains departing hourly from Union Station starting from 10:15 a.m. All non-peak and most weekend/holiday service is provided by buses. Weekend service was cut in early 2023, but resumed with 11 daily trips in each direction in September 2023

As of December 23, 2021, the entire length of the GO Transit Stouffville line (except for one crossing at the Markham/Stouffville border,[24] three crossings in the Town of Whitchurch-Stouffville,[25] and one crossing in the City of Toronto[26]) has train anti-whistling procedures implemented as the result of public outcry regarding the level of noise to which some residents were introduced as a result of the provision of increased rail service along the line.[27] The Canadian Rail Operating Rules currently requires trains to begin blowing train whistle warning signals a quarter mile[28] from every railroad crossing and continue to do so until the train enters the crossing[29] as a warning to motorists and pedestrians that the train is fast approaching. The 24/7 whistle ban prohibits train engineers operating on the line from performing this warning signal.

Every city served by the line had to apply to Transport Canada individually in order to stop whistling. The railroad authority Metrolinx worked closely with these cities to implement whistle cessation as quickly as possible provided that all safety requirements are met. To impose a ban on train whistle usage at railroad crossings, several safety upgrades had to be installed at each crossing in order to receive approval from Transport Canada. These safety measures include flashing lights, bells, and gates, signs warning the public that trains will arrive without additional warning, and removal of trees to increase sighting distance.[30]

It is important to note that even when train whistling at level crossings is prohibited, there are other requirements in the Canadian Rail Operating Rules which require trains to whistle, such as when encountering a crew of track maintenance workers on or near the railroad right-of-way. As anti-whistling does not extend to these factors, residents living in close proximity to the line may still hear the whistle from time to time.

It should also be understood that the elimination of train whistling at public level crossings causes an increase in liability against the city where a train accident causing injury, permanent disability, or death occurs. As it is a well-established fact that whistle bans will increase both the frequency and severity of accidents, the city where such an accident occurs would have to assume liability to which it otherwise would not be exposed.[31]

A key component to GO service expansion on the Stouffville line is grade separation. Grade separation is the building of underpasses or overpasses to separate road traffic from rail traffic by eliminating level crossings. Grade separation is one of the infrastructure improvements required to be completed in preparation for the GO Transit Expansion Program. There are several benefits of grade separation, the main one being that vehicles no longer have to stop for trains. By eliminating traffic conflicts, vehicular traffic flow through busy streets is improved once trains become much more frequent. A less important but still noteworthy benefit is that grade separation is the only solution that effectively removes the need for train whistling without compromising public safety.[38]

As of July 26, 2023, the Steeles Avenue East grade separation has completed construction.[39][40] In the near future, six more grade crossings will be grade separated: four in Toronto and two in Markham (right of way acquired for overpass with extension of Donald Cousens Parkway north of Major Mackenzie to terminate at Highway 48 deferred to 2026).[41] There is also another crossing in Toronto that is included in this project that will be closed instead of grade separated since it runs through the middle of a residential neighborhood and underpass or overpass construction is infeasible.[38]