What if Minneapolis-St. Paul had the London Underground?

Many people have complained that Minneapolis – St. Paul does not have a good transit network, or is not a “real” transit city. Well London does have a good network, and if any place is, London is a real transit city, so it is informative to compare.


This map overlays the London Underground network on top of the Minneapolis – St. Paul street network, keeping scale consistent. We centered Green Park station at Nicollet and 7th in downtown Minneapolis. Like London, the Twin Cities region is asymmetric, with more people to the west than the east. The Underground service is much denser to the west of London than the east and south (the south does have more surface rail though). Lines are spaced at 1 – 2 mile intervals, so many people can walk to stations, even in the far suburbs of Metro-Land.

The system is radial, though not perfectly. London also has lots of cross-connections, and some of the radials cross as well, far outside the city center, and both the Circle Line (which is no longer circular, but more of a spiral), and the recently upgraded orbital Overground services. Roth, Kang, Batty, and Barthelemy argue that it is a natural stage of evolution for subway networks, once radials reach a certain point, to build circle lines to enhance accessibility at non-central stations. Doing so creates new hubs.

Why does London have such an extensive rail network?

The first answer is obvious, it is about 3 – 4 times as populous as the Minneapolis – St. Paul region. London has 8.3 million people in the city and maybe 13.6 million in the larger metropolitan area. In contrast, Minneapolis – St. Paul has 3.8 million people in the greater Metro area (well beyond the 3.4 million in the 7-county Metro), with only 700,000 in the core cities.

The second answer is that it grew to its current size before automobile dominance, and so co-developed the system with the city, much like the streetcars in the Twin Cities. Unlike the streetcars, the rail system in London was largely maintained at its full extent.

The third answer is that it has a higher transit mode share, and thus greater demand per capita. The London Underground is about 250 miles (402 km). The Twin Cities LRT system collectively are 23 miles (38 km) long, so about 10% of the length. London serves about 3.7 million passengers per day. The Twin Cities LRT will serve about 70,000 per day once the Green Line opens, about 2% of the London Underground ridership. The public transport mode share for work trips in London is 41%, compared with 5% for the 7 county Twin Cities region.

The fourth answer is that as demand rises, it becomes increasingly cost-effective to use rail rather than buses to move increasingly large numbers of people, as the higher initial capital costs can be spread over more users, while the potentially lower per person operating costs become more important. Thus, not surprisingly, London moves a greater share of its transit users on rail than bus. Perhaps surprisingly, even in London, buses still move many more passengers than the Underground, at about 6 million per day.

It would be nice to see similar overlays, transit systems of City X overlaid on the street networks of City Y to aid in comparative analysis. (It would be really cool to see an online tool that does this for any pair of cities). When we travel, we see other cities, and try to make comparisons back home, but it is difficult. The cities you visit are not as familiar as the ones you live in. The modes of travel are almost always different (even a rental car is not the same as your own car). Thus scales get distorted. By comparing cities, we are better able to see what is possible.

For clarity, this map does not include all of the transit serving London. It excludes the surface rail, the Overground, the Docklands Light Rail, and Croydon Tramlink, as well as the extensive and excellent bus service. The map is from 2008, and so includes the East London Line as Underground, not as Overground. Some other minor changes are also ignored. Note, this is also a scale map of the London Underground, so it might look very different to those accustomed to the Beck map and its successors.

A movie of the evolution of the London Underground, as well as other movies, can be found here.

This article is cross-posted at Streets.MN

The Co-Evolution of London’s Land Use and Transport

updated August 25, 2009:
For those of you who doubt I am doing work over in London, I have completed two other papers (in addition to “Too Expensive to Meter” based on my research over here):

  • Levinson, David (2008) The Orderliness Hypothesis: Does Population Density Explain the Sequence of Rail Station Opening in London? Journal of Transport History 29(1) March 2008 pp.98-114.[download]
  • Network growth is a complex phenomenon. Some have suggested that it occurs in an orderly or rational way, based on the size of the places that are connected. David Levinson examines the order in which stations were added to the London surface rail and Underground rail networks in the nineteenth and twentieth centuries, testing the extent to which order correlates with population density. While population density is an important factor in explaining order, he shows that other factors were at work. The network itself helps to reshape land uses, and a network that may have been well ordered at one time may drift away from order as activities relocate.

  • Levinson, David (2008) Density and Dispersion: The Co-Development of Land use and Rail in London. Journal of Economic Geography 8(1) 55-57.
    JEG: [doi]
  • This article examines the changes that occurred in the rail network and density of population in London during the 19th and 20th centuries. It aims to disentangle the ‘chicken and egg’ problem of which came first, network or land development, through a set of statistical analyses clearly distinguishing events by order. Using panel data representing the 33 boroughs of London over each decade from 1871 to 2001, the research finds that there is a positive feedback effect between population density and network density. Additional rail stations (either Underground or surface) are positive factors leading to subsequent increases in population in the suburbs of London, while additional population density is a factor in subsequently deploying more rail. These effects differ in central London, where the additional accessibility produced by rail led to commercial development and concomitant depopulation. There are also differences in the effects associated with surface rail stations and Underground stations, as the Underground was able to get into central London in a way that surface rail could not. However, the two networks were weak (and statistically insignificant) substitutes for each other in the suburbs, while the density of surface rail stations was a complement to the Underground in the center, though not vice versa.

Perhaps more interesting for the non-academic, we (Ahmed El-Geneidy, Feng Xie, and myself of the Nexus group) have put together three quicktime movies

  • 1.The co-evolution of London population density and surface (National) rail
  • 2.The co-evolution of London population density and the Underground
  • 3.The co-evolution of London population density and surface (National) rail and the Underground

These can be accessed from here.

Touching In

“If you don’t touch in and touch out with your Oyster card, you will be charged the maximum fare”. This is the new rule implemented by TfL in November 2006 to ensure that people are paying the correct fare on the UndergrounD.
I have inadvertantly validated that they do in fact charge the maximum fare, returning home one day last month, all of the turnstiles at the South Kensington station were marked with a big red X and were open. Not sure how to touch in (I actually DID touch the Oyster card to the reader, but it wasn’t read, due to the thing causing the big red X), I, along with hundreds or thousands of others walked through. Touching out at Putney Bridge, I saw a £4.00 deduction rather than the normal £2.00. So I paid £2.00 for science. It is not worth my time to complain to TfL (though worth it to blog about)
The problem with this system is that it assumes the system is perfect. Now this is TfL’s UndergrounD, we know quite well the system is far from perfect, my estimate is that a given line has problems between 10% and 20% of the time.
The turnstiles have many of the same maintenance issue writ small. The reader can be down, even when it is up, there is no visual feedback that your card was read on many readers (the light/LED behind the green “Enter” sign is out), and the auditory feedback is impossible to detect in a crowded, noisy station. When I exit, Putney Bridge’s turnstile tells me how much is left, not all turnstiles do. When I enter or exit at South Kensington, the gates are open from the previous person who touched in or paid by ticked.
Another problem is the maximum fare rule. If I have already spent a lot on public transport today, or if I have an unlimited use pass, touching in and out really don’t matter (I assume, I have not tested this).
Is there a better solution? Clearly charging the minimum fare would encourage abuse.
Comparison with the same users daily travel patterns could be used to detect anomolies, but creates its own difficulties, and does not guarantee fairness as people may change patterns from day to day.
A single flat fare (as on buses) would avoid this problem, but would of course favor long over short trips. It also defeats the whole point of having smart cards, since a much simpler technology could be used to collect money.
A more reliabile ticketing/turnstile system would help, but may also slow down travelers (closing the gate quickly after a passenger goes through, delaying the next passenger as the gate must reopen). This is of course the better solution.

VMS: Variably-reliable Misinformation Signs

Variable Message Signs (VMS) are intended to provided information to travelers on roads (how long to nearby destinations, warning of an accident, there is an Amber Alert, please run a car with license plate XXX YYY off the road). In London they are used on underground and National Rail trains and at selected bus stops with the Countdown system installed.
I wish they were accurate.

Continue reading

With rail, you know where you’re going, … NOT

In the previous entry “On ‘A Streetcar Named Development'”, I noted ‘The more important concern is revealed by the closing quote from Teresa Wernecke, director of the Downtown Minneapolis Transportation Management Organization. ‘“With rail, you know where you’re going,? Wernecke said.’
I am here to tell you, that in London, on rail, you don’t know where you are going. Yesterday, returning home from Imperial College on the District Line, I boarded the Wimbledon-bound train at the South Kensington Station. The District Line roughly forms an 3–C Shaped network (all distorted though), The Edgware Road branch and the City branch come together at Earl’s Court (the two branches of the “C”), and then lines split again for Wimbledon, Richmond, and Ealing (the three prongs of the the “3”).
Well, before the train reaches Gloucester Road station, the conductor announces the train has been redirected to Ealing Broadway, and all passengers bound for Wimbledon (or points in-between) needed to change trains at Earl’s Court.
While this is not a big deal, walking from one train on the platform to another across the platform, it created a lot of confusion. Native Londoners were asking me (a newbie) what was going on.
Those dynamically rerouting the trains had a good reason for this (another Wimbledon-bound train was already at the Earl’s Court platform, one for Ealing must have been held up somewhere upstream), trying to balance service or flow of trains.
If this had only happened once, one might say, “that’s strange”. But in two months of semi-regular commuting this is the third time this has happened. I missed the announcement once and had to backtrack. This does not happen with buses.
The point is that (A) when you have a complicated system, this creates opportunities to dynamically reroute (on a single line system, the exercise would be meaningless), and (B) there is not something inherently more secure or informative about rail over bus, and may be found more on rail than on buses (I have yet to be on a bus which suddenly changed which route it was traveling on).