Are Elevated or Underground Metro Systems Better?

Chicago is one of the only cities in the world with elevated metro lines running through downtown. Why is that? Are underground lines better than above ground?

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Written by Dave Amos.
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[chow-chihuang]

As a rider, I prefer trains with a view. As a resident, I’d prefer they be underground due to the noise. There are pros and cons to each, but I’d rather have rail transit than none, so whatever gets built and used is fine with me.

[thomasblyth]

Its worth noting that on the noise front, a new concrete elevated line will be much much quieter than the 100 year old lines with steel supporting structures that we have in Chicago and NYC

[RoboJules]

The answer is that no one cares as long as it's grade separated. Elevated, Tunneled, Trenched, Fenced - it really doesn't matter. Those methods of metro constructions are just tools to utilize. Personally, I think it's best when cities construct their metros to address the geography it's running through. In Richmond, the Canada Line is elevated, as it's built on alluvial soil. In Vancouver, the Canada Line becomes a Subway as it runs through the mountain of the Burrard peninsula and Downtown Vancouver. Near the Airport, the Canada Line runs on the ground fenced off of traffic, as there's nothing there. The Canada Line also only cost us $2 billion for the whole system, and it's a 20km long automated metro system that connects Vancouver, Richmond, and the Airport, so if you utilize effective design, you can have a modern efficient system without spending $10 billion a line.

[erickpalacios]

As a mainly elevated transit system, I love riding the Skytrain in Vancouver. Especially on clear, sunny days with breathtaking views of the mountains dotted with the dense, urban construction at and around some of the stations.

[DavidTheScientist]

One thing I like about elevated trains are the views... You get to see and understand the city you're passing through. In contrast, with underground systems you go down one hole and pop out another, rather like a mole, with little sense for the distance or direction in which you've travelled, or what you've missed seeing in-between.

Also, modern elevated trains seem to be much quieter than the EL, presumably in large part due to the mass dampening and sound-blocking properties of the solid concrete bases on which they rest...

[Chrisd]

As a New Yorker, I absolutely love the classic look of an el train. Nothing beats it! Wish more cities in the U.S. had it

[usernameryan]

I live in Honolulu and have been following skyline extensively. There is nothing inherent about that project that required it to be so expensive. They’ve been dealing with lawsuits, expensive land, and it really is mismanaged (as everything is in Hawaii). Our constructions costs for anything is routinely way higher than anywhere else. Even road maintenance or construction is ridiculously expensive. The H3 highway, even though was built as a higher up bridge, was the most expensive highway built per mile in the US I believe.

If Honolulu would have tunneled the project, my guess is they would’ve spent over a billion dollars per kilometer. The train is now being constructed in the city and they are spending 496 million dollars to move the utilities down only one road. The costs for everything here is just insane.

[sethland]

You missed an important consideration: hydrology. Although there are subways in Chicago, The area was naturally a marsh not much higher than lake Michigan and the Chicago river. Flooding can be a major concern. Also the soil needs to have strong shear strength, preferably bedrock, otherwise construction gets really onerous to shore up the soil. Makes subways more expensive relative to build. This is why elevateds are prominent in Bangkok, Manila, and in tropical cities in general.

[SigmaRho]

Most metros in India that opened in the 2010s and 2020s are elevated but some of them like Bangalore, Pune, Lucknow and Ahmedabad had a limited number of underground stations in the city center. Other systems like Chennai and Delhi have extensive city center tunnels.

[bobbyswanson]

i love a good combination of both. there’s something cool about going through tunnels and popping up right at your destination, while you just can’t beat the view of trains riding above the street

[jonahg]

As a Chicago-born transit nerd, I love elevated trains and will take them above subways any day. It also means that drivers can see exactly how much faster a train can be (thinking of Blue Line and the Eisenhower) and that can spur more transit construction.
All that said, if a subway is what gets built, so be it. A metro is a metro.
edit: wrong highway thanks @A-M4

[CortexNewsService]

I used to live very close to the Red Line in Chicago's Rogers Park. You'd be surprised how quickly you get used to it. Sometimes I had to pause a convo depending on where I was in the apartment, but it just becomes background noise.

[LoveToday]

I like elevated because I get to know a city better and as a result can navigate much easier. I love Chicago's L system and look forward to the CTA having leadership that takes transit seriously.

[TikoVerhelst]

AS A DUTCH PERSON I think Rotterdam absolutely nailed this.
Basically the system is elevated most of the time, but underground in the city centre where above ground was impossible. The system is mainly used to connect suburbs to the city centre.
They treat it more or less like they do with trains. So sound shields whenever needed and a lot space around the stations anyway. (the metro stations often being major local bus stops as well)

Personally, I love taking the C line from Spijkernisse and slowly getting deeper and deeper into the city seeing the buildings getting higher and higher and higher!

I love the Rotterdam metro system, the public transport obsessed Netherlands has nothing like it! :P

[Starkus]

One great thing about elevated lines on the Subway systems in Berlin and Hamburg is also when they don't go directly above a street, there'll often go right over shops and restaurants. It's super cool being in a bar where the rooftop is basically a subway track. Also some of the best night clubs in Berlin are located within the elevation structure of the subway.

[bojstojsa]

Beyond the cost savings, a major advantage of elevated metro is that its infrastructure represents substantially less embodied carbon than tunneled metro, which can be so substantial that it may take decades for a new heavily tunneled metro line to save more CO2 emissions than was emitted during construction.

[emu]

5:11 ahh it is so cool that you filmed what was my stop for over 7 years! I probably watched one of your videos standing right at that platform. Love the focus on Chicago, here!

[tdb]

I visited Chicago a few years ago, it's such a cool place. It reminded me a lot of Melbourne, Australia (my hometown). The street grid, elevated tracks and huge number of skyscrapers really reminded me of home.

[crowmob-yory]

They both have their place. Underground is better in areas with extreme temperatures (such as Moscow or Singapore), while above ground is better in areas with high water tables (such as Miami or Honolulu). There are plenty of other reasons a particular track location might work better for certain areas, but geography is perhaps what influences above vs. underground the most.

[FoxBoi]

i think it shouldn't be such a dividing question. it should be a question for each part of each line. vienna has 6 underground lines. not a single one of them is entirely underground. 2 of them (u4 and u6) are mostly above ground. u1 and u2 are underground in the city center but as they go into the outer districts they come out of the ground and are elevated and sometimes also at grade.