The rise and fall of monorails - Why monorails are not more popular and why they are secretly a terrible idea.

Monorail, Monorail, Monorail!

A monorail by definition is a train that uses a single rail track. Some monorail systems use magnets to levitate the monorail car but many others use rubber tires to make contact with the rail. Funnily this latter design actually has more wheels than normal trains, requiring one to power the train and another two on either side to keep the car connected to the track.

So why build one? A monorail has several advantages over a typical duo railway line.

Monorails actually have the least visual impact of all elevated rail options. With a single track, they can seemly glide aloft those city streets and still let in plenty of sunlight compared to older overhead rail found in Cities like Chicago and New york.

Plus less material is needed to make a monorail and therefore it can be cheaper.

The monorail is one of the most efficient systems in the world, hardly breaking down and able to maintain around 99% uptime. It is also less expensive to operate than standard rail. This might have to do with many of the monorail systems being privately owned enterprises, subsidized by the tourist attractions they are affiliated with, rather than public government departments.

Alas… for as fresh and cool as they are, monorails have some pretty steep disadvantages.

In order to achieve stability, the “rail” IN monorail tends to be both significantly wider and taller than you would think based solely on the name.

Compared to regular duo rail, the loading gauge of the monorail cars is essentially the same, and thus there is not a massive benefit in slightly reducing the footprint of the railbed. The mass of the vehicles carrying the passengers, if the same as two-wheeled designs, will impact around the same amount of force and will require the same amount of construction.

This means the same depth for the pylons and the same weight-bearing pillars.

And bad news for Suspended monorails, that requires even more space to place their rail infrastructure.

Plus think about leveled crossings and movement at the ground & underground level. A monorail structure requires at least some elevation at all times, while duorails can crossroads with less than a foot depth required.

Despite appearances, when underground a monorail requires more superstructure than standard duo rail.

Again, suspended monorails are even worst in all three scenarios.

Monorails make sense if the line is elevated nearly 100% of the track, but beyond that, there are very few transport corridors that make sense. Even at Disney World, they used a monorail to connect between different resorts, but when it came to its Hong Kong park, they opted for duo rail due to an underground section and connection with existing other rails.

And there is the technical challenge of switching tracks. On a duo-rail system, because of the way the train sits on top of the tracks, they can criss-cross over each other to let other trains pass or to swap out engines. On a monorail, because the monorail cars wrap around the entire tracks, you can't entirely use the same techniques.

Cross over tracks for monorails are not impossible... they are just really slow and costly to build. Plus, it is yet another component that can break down.

Monorails got really popular around the middle of the last century, with cities building the retro-futurism transport options to make a statement...

But by the 1970s and 1980s, a monorail was seen as a failed and disappointing public transport system and it was beaten out by cheaper alternatives, such as buses, trams, and existing trains. There where only a few places where a monorail made sense over other options, and they were built there more as a stunt than an actual public transport option... like at theme parks or tourist areas.

In fact, in the last few years, cities around the world went out their way to get rid of monorail programs.
In summary, to answer the question why did monorails not take off, and why did they never really become the transport of the world of tomorrow?

They are a niche transportation mode, much more expensive than light rail or streetcars, much more visible than subways, much less flexible than buses, much more difficult to engineer than two-rail based systems and while better than elevated trains in terms of blocking out the sky, they still block out the sky.

But don't despair, plenty of monorails are still slowly being built around the world today in China, Istanbul, and Malaysia.

China’s BYD and Canada’s Bombardier plan to add 295 miles of new track by the end of 2020, and to put that into perspective, since 1900 only 254 miles of track has been built globally.

Speaking to media, LA mayor Mayor Eric Garcetti said “With a small footprint, with electric motors, safety for both earthquakes and access, it could be on the table.