The Hyperloop and Marchetti’s constant

(aka how far can a rollercoaster on steroids get you in 30 minutes)

“An hour wide”

Back in the first lecture, we briefly visited Marchetti’s constant and how this limited travel time limits urban growth.

Marchetti’s constant: the average commute time per person is about approximately 1 hour a day (so about 30 minutes either way if you’re only moving to and from work)

Essentially, this implies that most cities remain an hour wide simply because many people (especially those who live in and around regions named Woodlands and Pasir Ris) instinctively refuse to exceed a daily “travel time budget” (Marchetti, 1994). This, in addition to the factors discussed in the same slide, limits the size a city can grow to.

That being said, it is possible for commute times to stay the same even as a city grows bigger. A possible reason, as proposed by Anas (2014), may be the behavioural switch to modes of public transport which reduces traffic congestion and thereby travel times. If you’re interested, this article gives a good summary of the phenomenon.

Other than behavioural change, another (more obvious) way that commute times can drop is an improvement in the speed and efficiency of available transport modes. But given that our cars, trains, buses and planes probably aren’t going to get much faster than they are right now, surely cities can’t expand that much… can they?

Another mode of transportation?

From the brilliant mind that brought us Paypal, Tesla motors, SpaceX and much more, comes a new concept for a high-speed transportation system.

For those who haven’t already heard or read about it, the Hyperloop is, as Elon Musk puts it, “a cross between a Concorde and a railgun and an air hockey table” (Speed, 2015). Like something out of the popular children’s cartoon “the Jetsons”, the Hyperloop will transport passengers through capsules within a tube system at amazing speeds.

Capable of moving close to the speed of sound (1220 km/h), the Hyperloop will transport passengers between Los Angeles and San Francisco (600 km) in a little over 30 minutes (Musk, 2016). To contrast that to Singapore, it would be the equivalent of moving from the east to west coast (~50 km) in about 3 minutes. (Here’s an idea: toss the Cross-Island Line and build a Hyperloop along the proposed rerouted route. An additional 4 minutes would become… 6 seconds?).

LA to SF
A car ride from Los Angeles to San Francisco would take about 5 hours and 41 minutes, about 11 times slower than the Hyperloop. Source: GoogleMaps

Implications on city limits

As much as I would like to continue writing more about this amazing concept (and its potential issues), perhaps I should go back to how this relates to urban limits.

The Hyperloop, once developed, could be a game-changer in urban development. If 30 minutes in a car at 100 km/h would bring you 50 km from the city centre. Imagine where 30 minutes in the Hyperloop would get you (Answer: very far).

For cities which are mainly limited in size by commute time, the technology could allow for a much greater expansion of their city limits: urbanites can now live much (much) further from the city centre and still reach their work place on time. Might we see urban sprawl happening in these Hyperloop-connected cities? And might this change our ideas of what a “sustainable city” is (especially since the Hyperloop will likely be run on solar power)?

Of course, there are many other factors to consider such as geographical and bioregional constraints when determining a city’s limits. Still though, I believe that the Hyperloop has the potential to significantly change urban transport and development as we know it.

Or maybe all we need is just a new Marchetti’s constant…


Anas, A. (2014). Why are urban travel times so stable? Journal of Regional Science, 55(2), 230-261.

Marchetti, C. (1994). Anthropological invariants in travel behavior. Technological Forecasting and Social Change, 47, 75-88.

Musk, E. (August 12, 2013). Hyperloop alpha. SpaceX. Retrieved February 12, 2016, from

Speed, B. (January 21, 2015). Elon Musk’s Hyperloop might actually get built. Retrieved February 12, 2016, from

2 thoughts on “The Hyperloop and Marchetti’s constant

  • February 15, 2016 at 6:50 am

    whoa ! interesting and kind of mind-blowing !

    but, how realistic is this concept ? from what i read, travelers could feel very uncomfortable, if not outright sick or worse. and what are the environmental impacts of building these systems ? would they run on existing infrastructure ?

    what about the bullet trains ? are they a more viable alternative for urban commutes ?

    • February 18, 2016 at 6:34 am

      Yup those are the two main concerns I’ve read about as well.

      I believe they are aware that the passengers will experience high g-forces during transport and are currently working on solutions to counter that. Not too sure how that’s going.

      As for environmental issues, the permanent structure required for the Hyperloop system (akin to an overground MRT in Singapore) may have some possible impact on surrounding wildlife (e.g. fragmentation). That being said, the energy efficiency and cost of the Hyperloop is much lower compared to any other form of transport, bullet trains inclusive.

      The Hyperloop will also be run on solar energy generated by solar panels located on top of the tube.

      Compared to a bullet train then, I believe the Hyperloop will probably be the greener option… although the few kinks it has to work out may make it less viable for now.


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