This is about being out in the open – and when planning a major subway, looking for ways to balance what’s above and what’s below.

That’s when planners, including those working on the new Ontario Line project, can look at plenty of great examples of routes from around the world when it comes to figuring out how to best deliver a transit line in this day and age.

When listing the benefits of subways, top-of-mind items include speed, convenience, more connections and avoiding street traffic.

If you’ve travelled on the TTC Line 1, along Yonge and north of Bloor, you’ve experienced (and welcomed) the daylight, as an added benefit, going through above-ground sections at Davisville and Rosedale stations. These sections break up the dark, underground ride through the city. 

“You get some light above grade, the views you get are much different and there is a non-claustrophobic type environment, a lot of customer experience attributes that get improved when you are in the open air” said Malcolm MacKay, program sponsor for the Ontario Line.

Line 1 and Line 2 have seven stations each with tracks at or above surface level.

For example, a stretch through the west end of the city rises above the parking lots behind Bloor Street, in and out of Keele station, back underground into High Park station, exiting above ground and then going under Bloor West Village.

The in-and-out routing was a response to the topography of the neighbourhood north of High Park, which has as dramatic a slope as the name implies. If subway tracks were laid at the same angle as Bloor Street, as the road goes uphill towards the main entrance to High Park and TTC station at the top, they would be too steep for the trains.

“Gradients made it prohibitive to stay underground, approaching High Park,” said Michael Tham, deputy technical director for the Ontario Line. “You couldn’t dig down enough and it would have been impossible to build at the time because of how deep you would have had to go below High Park.”

By Canadian and international standards, the above-ground sections of the TTC subway system are very common. Elevated and at-grade transit lines are nothing new and have been proven around the world as a way to improve transit connections and strengthen communities.

Here in Canada, Vancouver’s SkyTrain offers many great examples of elevated stations and guideways that fit nicely into surrounding neighbourhoods. The majority of the system features at-grade or elevated tracks, and it’s currently the longest rapid transit system in Canada despite the fact that construction only started in the 1980s.

TransLink runs the above-ground SkyTrains across Metro Vancouver. This network has grown to include 53 stations serving the Expo, Millennium and Canada Lines.

In Vancouver, modern urban design principles resulted in the construction of elevated rail stations and lines that are pleasant additions to neighbourhoods, giving passengers a quick and efficient ride.

While most of the tracks are above ground, a stretch below Dunsmuir Avenue takes advantage of a tunnel that was built for steam engine trains in the 1930s. From 1955 to 1979, it was used to take empty passenger trains back to a yard for cleaning and servicing. When it was no longer needed by VIA, this valuable piece of rail infrastructure saw new life as part of the Expo Line, which opened in December 1985, with two downtown stations (Burrard and Granville) built into the tunnel.

This is a great example of how transit planners do not think of exclusively above ground or below ground lines as they plan the best route. They do what makes sense with the local geography and take advantage of existing spaces, rail lines and other infrastructure when possible.

In Toronto, the new Ontario Line will run underground through parts of the city, using existing ground-level space in parts of the GO rail corridor and new elevated structures in the city’s north end, where the Don River valleys add complexity to the route.

A tunnel that would be deep enough to safely go under the Don River in both the east and north segments would require digging very deep below the surface, making for very long connections to buses at street level and longer construction timelines. Running along elevated structures solves for this.

Montreal is also adding to its rapid transit system with a new line that will run both above and below street level. The new Réseau express métropolitain (REM) will be a fully automated light rail transit system with four lines running over 67 kilometres, with 26 stations.  Like the Ontario Line, some sections will use existing rail corridors. While, like Vancovuer’s Expo Line, it will use an existing tunnel, most of the rest REM will be elevated.

REM is the largest public transit project undertaken in Québec in the last 50 years. The first trains are expected to start running in 2021

Around the world, transit agencies have been adding above-ground lines to their networks for decades.

This is true in London, England. Despite the “Underground” branding, most of the network has always run over surface tracks. Since 1980, London has massively expanded its subway system, adding about 80 kilometres of new tracks on five lines. Only about half of the new lines and extensions are in tunnels. More than a quarter are alongside existing commuter rail lines, much like stretches of the Ontario Line which will use the GO rail corridor. Most of the remainder are elevated, with some new surface tracks.

London’s Docklands Light Railway (DLR) is a highly popular and reliable transit system railway that began in the 1980s. It now has nearly 40 kilometres of track, most of which is above ground.

The line serves an area just east of Central London which, like Toronto’s Port Lands, was underused for decades as shipping needs changed. As the area was redeveloped, the DLR emerged as the best solution for linking this area to the rest of London.

The DLR was a critical part of London’s plans to host the 2012 Olympic Games. It linked fans to the Olympic Park and its stadium, which is now home to West Ham United of soccer’s Premier League.

Other notable places on the DLR include the Canary Wharf office complex, the Tower of London, London Bridge, and the London City Airport.

Like almost all new subway systems, the DLR was built to operate automatically from a central control system, without train drivers. The technology was designed and manufactured in Toronto and is also used on lines in Beijing, Singapore and many other cities around the world.

New housing has been built close to the DLR tracks, and even over the tracks, along the line. This works well for residents because today’s electric train technology is so much quieter than diesel engines, with no local emissions. Automated train operations also minimize human error related to braking, preventing “hard stops” and resulting in less wear and tear on the wheels. This further reduces noise and vibrations when trains come to a stop at stations.

Building above ground can often mean fewer disruptions for neighbourhoods surrounding the construction when compared to digging below.

Utility lines that deliver water, power and telecommunications services run under cities, as do sewer lines. They often have to be moved before tunnel construction, resulting in service disruptions for the surrounding neighbourhoods, not to mention impacts to traffic and surrounding properties to accommodate work crews and equipment.

Since above-ground construction is faster and less complex, construction crews can also complete their work sooner.

“At-grade stations are generally less expensive and quicker to construct because you don’t need to spend as much time to excavate the soil,” said Tham. “You get to start building the structure of the station sooner, see visual progress sooner and complete the major works sooner.”

One of the Ontario Line stations that will benefit from this approach will be its western terminus at Exhibition Place. The existing above-ground Exhibition GO station will be upgraded to accommodate both Ontario Line trains and expanded GO train services.

Recently, Metrolinx released a report about the work needed to make that happen. Those who want to share their thoughts on the report and learn more about how Metrolinx will bring the neighbourhoods of Liberty Village and Fort York into the subway network can visit MetrolinxEngage.com/OntarioLine.