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Genuinely Great Geography

Updated: Aug 7, 2023

If Canada gets serious about high-speed rail, the impediment won’t be the topography

There seems to be this belief going around that building high-speed rail has to be exorbitantly expensive. As we’ve covered in previous blog posts, many of the factors that lead to exorbitant costs have nothing to do with physical reality and have everything to do with politics, planning and management.


However, is the physical environment really that amenable for high-speed rail in Eastern Canada? Or will we have to spend millions extra on tunnels and viaducts to make it work?


What is good terrain for high-speed rail?

To understand what is good terrain for high-speed rail, we need to understand how high-speed rail trains work.


High-speed rail trains don’t like steep climbs and they don’t like tight curves.


Though high-speed trains can climb steeper grades than freight trains, they typically can only climb grades of around 2% over long distances and 4% over short distances. (In contrast, it is not uncommon to see roads with inclines 7x steeper). Going over even simple hills is a challenge for high-speed rail.


If you can’t go over, why not go around? This is what freight railways do, however, tight curves limit speed and freight trains don’t need to go fast. Trains can only travel so fast over curves before they cause passenger discomfort and risk causing a derailment.


In order to allow travel at high speeds, curves need to be very broad. For example, for a train to safely travel at 320 kph on a curve with a standard cant (80 mm), it needs to have a radius of over 5 km. This can be remedied to an extent by increasing the cant of the track (for our previous example, increasing the cant to 180 mm reduces the required radius to 3.5 km), however, doing so excludes these tracks from freight use. In addition, tilting train technology doesn’t really work at high speeds. The map below illustrates how large the curves need to be.

So if you can’t go over or around, the only option left is through. And this is what many high-speed rail routes do; they build tunnels and viaducts to traverse difficult terrain. However, as you can imagine, this is costly. Roughly speaking, high-speed rail requiring extensive earthworks costs 4 times more than high-speed rail over gentle terrain, viaducts 8 times more and tunnels over 11 times more.


However, it’s not enough for the terrain to be flat in order for it to be great for high-speed rail. It should also be fairly empty. Broadening curves in built-up areas entails building costly viaducts or tunnels and noise concerns from nearby residents can increase sound-proofing costs and limit top speeds.


Saying an empty area is desirable for high-speed rail might sound paradoxical. After all, high-speed rail only makes sense when there is a sufficient concentration of people generating a sufficient number of trips. It comes down to where the population is concentrated. If a region’s population is concentrated solely in major urban centres with empty rural areas between them, this means upgrading the corridors between the cities to high-speed rail standards should be relatively straightforward. In contrast, if the rural areas are densely populated with many villages, this makes upgrading much more difficult.


A Look at Eastern Canada’s Geography

So the ideal for high-speed rail is flat and open terrain.


Well, guess what Eastern Canada has a lot of? Flat and open terrain.


If we look at the elevation difference between the highest and lowest points of the proposed High-Frequency Rail corridor between Toronto and Quebec City, we see that the difference is only around 200 m.


Another indicator of the flatness of the terrain is the geometry of existing freight corridors. If a freight railway has a straight corridor, it is a very good sign that the terrain is flat (as freight trains typically handle even shallower grades than high-speed rail). We can see that the corridor contains main straight sections, most notably between Ottawa and Montreal. We can also see that the most challenging sections will be between Toronto and Ottawa, particularly around Sharbot Lake.


This map also illustrates why the interior route chosen for High-Frequency Rail is more cost-effective than a route along Lake Ontario. As you can see, there is less straight track and the concentration of settlements means that implementing high-speed rail here would likely be more expensive.


Comparisons with the Terrain of Other High-Speed Rail Countries


How does Eastern Canada compare with other high-speed rail corridors around the world?


The section of high-speed rail between Madrid and Barcelona is particularly useful as it contains a similar population and has a similar length to the corridor between Toronto and Montreal. As we can see, with the exception of the major cities, the corridor is fairly empty. However, unlike Eastern Canada, Spain’s high-speed rail corridor passes through challenging terrain. The difference in elevation between Madrid and Barcelona is over 1000 m! Despite the challenging terrain, this line was built at a cost of $22 M CAD (2023) per km.


Another useful comparison for Eastern Canada is with our neighbours to the south. The Northeast Corridor in the United States is where the high-speed Acela service runs and traverses relatively gentle terrain. However, the corridor runs through dense rural areas. Upgrading the corridor to higher speeds would likely require extensive viaduct and tunnel sections.


Is there another place in the world that has gentle and empty terrain? Yes, in France between Paris and Lyon and this was built at a cost of only $12 M/km (CAD 2023).


The Last Word on Geography


When I first started researching high-speed rail in Eastern, I was pleasantly surprised to see how favourable the geography was. Combined with the region’s favourable demographics, it feels almost criminal for our country to not take advantage of it.


We can seize this opportunity and realize the most transformational public works project in a generation, or we can continue to make excuses for why we don’t.


If we fail, it will be because we failed, not because our country’s landscape did.


If you want to learn more about how high-speed rail can become a reality in Canada, please check out Build It Right - A Study on High-Frequency Rail/High-Speed Rail in Canada.



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