A US Density Revolution?

These two things are connected!

In major cities and some states across the US, the tide seems to suddenly be turning in favor of density.  James Brasuell at Planetizen has a thorough survey of these efforts.  Read the whole thing.

An inescapable trend emerged in recent years and months: a large and growing number of communities are now engaged in comprehensive plans and zoning code revisions, and they’re doing that planning work in the hopes of creating a future that is fundamentally distinct from the 20th century model of planning.

But the revolution Brasuell describes is about much more than planning documents.  The story is political:  In response to the housing crisis, both city and state politicians are producing legislation that makes it easier to build densely by:

  • reducing off-street parking requirements, which makes denser development pencil out and can also make units more affordable
  • streamlining transit-oriented development, including around frequent bus corridors and
  • most controversially, allowing more density in neighborhoods that have long been legally protected as exclusively for single family homes.

All this is great news, not because everybody wants to live at high density but because more people want it than can currently afford it.  The extreme cost of living in dense and walkable cities is the sound of the market screaming at us to build more of them, and finally that’s becoming possible.

From a transit perspective, I have one note of caution when it comes to upzoning absolutely everywhere.  Most cities have places that are hard for transit to get to, and where a few more people will create transit demand that is very expensive to serve.  Sometimes they are physically hard to reach: long cul-de-sacs, squiggly streets, etc.  But sometimes too they are so sparsely populated that they are poor transit markets and adding a few more people isn’t enough to make them better.

Gentle upzoning of single-family areas — allowing second and third units on formerly single-family parcels — is mostly helpful, but not always in these tough spots.  In any case, serious density must be organized around the frequent transit network — bus and rail — so that more people end up in places where transit can be really useful to them.   Don’t know where yours is?  There should be a map of it somewhere, reflecting a policy adopted by both your transit agency and your city government!  It should be on the wall in both the transit agency and the city’s planning and traffic offices.  (See Chapter 16 of my book, Human Transit, for more on this tool.)

Transit is expensive.  It succeeds when it can run in straight lines through dense and walkable places, so that it has enough ridership over a short enough distance that it can afford high frequency.  A policy frequent network, agreed upon by the transit agency and the city government(s) and manifested in both zoning and traffic planning, was critical to jumpstarting the growth of transit in Seattle, which is now one of the US’s great success stories.  It could make a difference for your city too.

2 Responses to A US Density Revolution?

  1. RossB March 1, 2019 at 11:26 am #

    Most cities have places that are hard for transit to get to, and where a few more people will create transit demand that is very expensive to serve. Sometimes they are physically hard to reach: long cul-de-sacs, squiggly streets, etc. But sometimes too they are so sparsely populated that they are poor transit markets and adding a few more people isn’t enough to make them better.

    I agree. But by and large that is not the area that is changing. For years there have been plenty of apartments in the suburbs, as well as relatively densely populated suburban developments (new housing tracts with smaller houses or townhouses). Unfortunately, these are often scattered about, creating the kind of mess you are talking about. Density that is higher than rural, yet not as high as a typical city built before zoning was so pervasive (a city with a mix of small lot houses and brick apartments). In that case, the added density is likely worse for both the environment and transit. Not enough density to provide good transit, but enough to cause traffic jams. It is especially tough because these areas are farther away from major destinations, making transit even less likely (because it is more expensive to provide). The one good thing is that it does provide for cheaper housing.

    But it isn’t necessarily what people want. The zoning changes that you refer to are simply a reflection of the social changes that have occurred for the last 20 years or so. Cities don’t suck (to quote a headline from the 90s). In fact, most of them are extremely popular. Folks want to move into the city, and are willing to sacrifice a big yard to get a place there. It isn’t even clear whether big yards anywhere are popular. The days of the housewife are gone, which means that both parents are busy spending their weekends catching up on errands or shuttling the kids around. Who wants to spend it dealing with a big yard? In any event, you can can see that in cities like Seattle, townhouses in the city — even areas once considered “ghettos” — are a lot more popular than big houses on big lots in the suburbs. Of course people want more house, but they are willing to sacrifice size (and certainly yard) for being in a more urban setting. The zoning changes are simply reflecting that, as a new generation has basically said “enough already” and rejects the Leave it to Beaver world of the past.

    This means that these changes will likely work out just fine for transit. The places where people want to live and the places where zoning laws are changing to accommodate them are largely within the city, on streets built before cul-de-sacs were common. Minneapolis proper is pretty much all a grid, while outside the city limits (where the laws aren’t changing) is not. Likewise with Seattle, which means that if Seattle ever liberalizes their zoning (i. e. allows more density in the vast majority of the city which is zoned as single family housing) then transit will improve as well.

  2. Ian Mitchell March 12, 2019 at 10:15 am #

    Connectivity, even if it doesn’t serve transit, is necessary to improve, especially to better serve increasing density.

    It’s hard to get 25 feet of right-of-way to connect cul-de-sacs or lollypop streets hither and thither, but 5′ for a pedestrian or bike path? Easy.

    That path can cut a walk to the bus stop in half.

    It can make it possible to beat a car on a bike, or to walk a mile without seeming bohemian or deviant.

    It may make density work, even without putting any more people on transit.

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