Heterogeneity of Preferences

The public transit conversation is full of statements like “passengers don’t like to transfer,” or, in quantified terms, “passengers perceive a minute transferring to be equivalent to 1.75 minutes on a moving vehicle.” But what does this exactly mean? It’s not a statement that literally every passenger has a transfer penalty factor of 1.75. Different passengers behave differently. At best, it’s a statement that the average passenger on the current system has a transfer penalty factor of 1.75, or alternatively that the aggregate behavior of current passengers can be approximated by a model in which everyone has a transfer penalty factor of 1.75. Understanding that different people have different preferences is critical to both the technical and political aspects of transportation planning.

I talked about the heterogeneity of transfer penalties three years ago, and don’t want to rewrite that post. Instead, I want to talk more broadly about this issue, and how it affects various transit reforms. In many cases, bad American transit practices are the result not of agency incompetence (although that happens in droves) but of preferential treatment for specific groups that have markedly different preferences from the average.


The universal symbol of disability is the wheelchair. Based on this standard, every discussion of accessible to people with disabilities centers people in wheelchairs, or alternatively retirees in walkers (who tend to make sure of the same infrastructure for step-free access).

However, disabilities are far broader, and different conditions lead to dramatically different travel preferences. One paper by the CDC estimates that 20% of US adults have chronic pain, and 8% have high-impact chronic pain, limiting their life in some way. People with chronic pain are disproportionately poor, uneducated, and unemployed, which should not be a surprise as chronic pain makes it hard to work or go to school (in contrast, the one unambiguously inborn socioeconomic factor in the study, race, actually goes the other way – whites have somewhat higher chronic pain rates than blacks and Hispanics). Another paper published by BMJ is a meta-analysis, finding that depending on the study 35-51% of the UK population has chronic pain and 10-14% has moderately to severely disabling chronic pain.

I’ve only talked to a handful of people with chronic pain – all of working age – and the best generalization that I can make is that it is impossible to generalize. The conditions vary too much. Some find it more painful to drive than to take transit, some are the opposite. Some have conditions that make it hard for them to walk, some are fine with walking but can’t stand for very long. To the extent the people I’ve talked to have common features, they a) have a strong preference for rail over bus, and b) require a seat and can’t stand on a moving vehicle for very long.

Work status

The best use case for rapid transit is getting people to work in a congested city center at a busy time of day, ideally rush hour. Off-peak ridership is generally cheaper to serve than peak ridership, but this is true for all modes of transportation, and public transit tends to be relatively better at the peak than cars. Per table 2 of the Hub Bound report, as of 2016, 19% of public transit riders entering the Manhattan core do so between 8 and 9 am and 43% do so between 7 and 10 am, whereas the corresponding proportions for drivers are 6% and 18% respectively.

The upshot is that people are more likely to ride public transit if they work a salaried job. This is especially true in the middle class, which can afford to drive, and whose alternative is to work at some suburban office park where car ownership is mandatory. In the working class, the distribution of jobs is less CBD-centric, but the ability to afford a car is more constrained.

The social groups most likely to drive are then neither the working class (which doesn’t own cars anywhere with even semi-reasonable public transit) nor the professional working class, but other social classes. The petite bourgeoisie is the biggest one: small business owners tend to drive, since they earn enough for it, tend to have jobs that either virtually require driving (e.g. plumbers) or involve storefronts that are rarely located at optimal locations for transit, and need to go in and out at various times of day.

Another group that’s disproportionately likely to drive is retirees. They don’t work, so they don’t use transit for its most important role. They take trips to the hospital (which is bundled with issues of disability), which can be served by buses given that hospitals are major job centers and non-work travel destinations, but their other trips tend to be based on decades of socialization that have evolved haphazardly. The urban transit network isn’t likely to be set up for their particular social use cases.

Consensus for whomst?

I bring up small business owners and retirees because these two groups are especially empowered in local politics. When I lived in Sweden, I could vote in the local and regional elections, where I had no idea what the main issues were and who the candidates were; I voted Green based on the party’s national platform, but for all I know it’s not great on Stockholm-specific issues. Figuring out the national politics is not hard even for a newcomer who doesn’t speak the language – there are enough English-language news sources, there’s social media, there are friends and coworkers. But local politics is a mystery, full of insider information that’s never spelled out explicitly.

What this means is that the groups most empowered in local politics – that is, with the highest turnouts, the most ability to influence others in the same constituency, and the greatest ability to make consistent decisions – are ones that have local social networks and have lived in one place for a long time. This privileges older voters over younger voters, and if anything underprivileges people with disabilities, whose ability to form social and political connections is constrained by where they can go. This also privileges people with less mobile jobs – that is, shopkeepers rather than either the professional middle class or the working class.

With their greater local influence, the most empowered groups ensure the transportation that exists is what is good for them: cars. Public transit is an afterthought, so of course there is no systemwide reorganization – that would require politicians to care about it, which interferes with their ability to satisfy the politically strongest classes. But even individual decisions of how to run transit suffer from the same problem when there is no higher political force (such as a strong civil service or a national political force): bus stops are very close together, transfers are discouraged (“we oppose the principle of interchange” said one left-wing group opposed to Jarrett Walker’s bus redesign in Dublin), rail service is viewed more as a construction nuisance than a critical mobility service, etc.

Models for transportation usage take into account the behavior of the average user – at least the average current user, excluding ones discouraged by poor service. However, the political system takes into account the behavior of the average empowered voter. In the case of local politics, this average voter rarely rides public transit. When city political machines run themselves, the result is exactly what you’d think.


  1. Eric

    Nice post. You usually write about technical things, so it is interesting to see a quality analysis of a social phenomenon.

    I guess the next question is: how do we change this?

  2. dhdaines

    The flipside of this is that there is a huge potential for any candidate or party that can figure out how to mobilize the non-traditional municipal vote, and this can usher in a transit-friendly, progressive administration. You can see this in a number of Canadian cities, starting with Vancouver and Calgary, and more recently in Montreal. I would guess that having municipal political parties which don’t align with the national ones might be a factor in this.

    • Alon Levy

      Yeah, Canada manages to have ideological party politics at the provincial and urban levels that don’t have to align with national politics. And the UK and France have the same party politics at all levels, but at least until the last few years London and Paris voted pretty close to the rest of the country, so there was regular alternation of government.

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