“Spatial Mismatch” and Why Density Alone Isn’t Enough

Density, density, density. It’s something of a mantra in sustainable transportation circles. But in today’s featured post from the Streetsblog Network, UrbanCincy points to the cautionary example of Atlanta — a place that could perhaps best be described as dense sprawl.

ATL_Skylines.jpgThe skylines of Atlanta. Photo by mattsal88 via ImageShack.

What has happened in Atlanta is something that should be learned from. Atlanta is arguably the king of sprawl in modern day America, but some might say, well Fulton County has a higher population density than does Hamilton County. Similar arguments can be applied to other less urban regions than Cincinnati. The fact is that Fulton County is just about built out with the exception of some land in the far southern reaches of the county. Furthermore, this built-out county has extraordinarily dense suburban areas including the central Perimeter area which includes 30-story office towers, residential towers and 12-lane highway systems to boot. The traffic is abysmal like much of the rest of Atlanta and the problem is only going to get worse.

The reason is a combination of densities and form. The suburban areas of Atlanta, and even much of the urban areas, are almost entirely
car-dependent. So a low-density suburban area that is car-dependent is one thing, but a high-density area of the same makeup is nightmarish. The "spatial mismatch" is exacerbated to a degree seen nowhere else in America than Atlanta and Los Angeles (Los Angeles County is the most populated county in the country at 9+ million). The people living in one area are working in another creating a spatial mismatch that is exacerbated by the high densities. They are not walking, biking or taking transit to a level enough that would offset its densities.

When you hear of the next "new urbanist" neighborhood on the fringes of a metropolitan area, or the next lifestyle center that pitches itself as being the next best thing to an authentic urban shopping experience, be wary. These are not real communities where store owners live in addition to running their business. The residents are most likely hopping in their car that is parked nicely within one of their two (or more) dedicated parking spaces and driving into the center city for work.

Higher densities in our suburban areas are not the answers to our sprawl issues. A correction of the spatial mismatch is what’s needed to truly create a sustainable metropolitan area. Natural systems need to be preserved in their truest form and our most fertile food-producing regions need to be maintained for their highest and best use. Higher densities in the core with high-density satellite neighborhoods connected by high-quality transit options are the best possible solutions.

Other news from around the network: Kansas Cyclist reports on efforts in Iowa and Colorado to ban bikes — that’s right, ban bikes — from some roads. Meanwhile, CommuteOrlandoBlog is back from a bike trip through Amish country and has a very thought-provoking post on the culture of speed vs. the culture of trust. And Trains for America links to a debate over the relative merits of high-speed and maglev trains.

  • DJB

    Isn’t this just saying you need density and a mixture of land uses. Straight out of Jane Jacobs right? Density is needed to support many local businesses withing walking/biking/transit distance and better transit service, but density alone isn’t enough in the sense that the zoning has to allow for a degree of use mixture, to allow density’s potential to unfold itself.

    We do need to densify our suburbs, but it won’t reduce VMT and promote alternatives to solo driving as well as it should without the will to mix up the land uses.

    Density can follow transit but transit can also follow density. You often have to build one first even though they work best together.

    Atlanta isn’t as bad the quote makes it seem. The 2000 census shows that 15% of trips to work in that city were by transit, 3.5% of people walked to work, 1.3% went by bicycles and such, 3.8% worked at home, and 12.4% carpooled. Thus, 36% of commuters to work didn’t drive alone. That’s more than a lot of American cities can say.

  • James

    I think part of the point is that there is sort of a “purgatory” of density that is too low for viable rapid transit with short headways and high quality service, but too high to be able to get around easily by car. I think that this dead zone occurs somewhere between 4,000 and 12,000 people per square mile. Christopher Leinberger has written in-depth on this topic but uses floor area ratios as the variable rather than density. We have plenty of places in the NY metro area like this – much of suburban North Jersey and Nassau County spring to mind. You need a car to live there, yet they are miserable places to drive. Hell, Staten Island falls into this zone as well in large part.

  • DJB

    That’s a good analogy. The path to heaven lies through purgatory. But at least purgatory is better than burning hopelessly in hell 🙂

    You usually can’t get to the densities that support the best transit without going through that middle phase where lots of people are still trying to drive.

    I say do it anyway. If grinding traffic to a halt for a while is the price of making cars a choice instead of a virtual necessity (through densification), do it.

    You can’t make an omelette without breaking a few eggs.

  • The truth is that density has absolutely nothing to add to a city except creating the potential demand for more complex markets. If instead of driving an hour from your subdivision to your job in the office park, you drive an hour from your condo to your job in the edge city, nothing has been gained except Corbusian gigantism.

    People see New York as a dense place and they immediately assume that it is density that makes it great. The relationship goes the other way around, it is because it is great that it can be dense.

    Forcing cities that aren’t great to go dense is just making everything worse.

  • Is there something spiritually wrong with medium density areas? Skyscrapers are culturally pretty lousy; they manage to capture much of the vitality of the suburbs combined with the easy-going lifestyle of a dense city. Of course you don’t need to go as far as a skyscraper to get good density; but still I think the happy medium *isn’t* just density density density.

    I would say we need a more fractal approach to density — homogeneity sucks at all levels. You need parks (essentially 0 people per square mile) next to dense areas, you need businesses next to people, but there’s nothing wrong if some people are just next to people. But with a fractal landscape — one without a designed center, one with clumps of activity and clumps of inactivity — you need transportation that can adapt to the changes, adapt to all the needs of people in all those areas. Transportation that can adapt to children and commuters and shoppers and tourists and the huge number of simply random trips people make for whatever reason. To a degree cars can offer that, as can bikes, though transit has a hard time.

    Maybe the changing trends of the last fifty years suck, but regardless, transit couldn’t keep up with those trends; with big box stores and suburbs and suburban business centers. I think trends are changing, another phase of development is slowly taking place, but it’s organic, it’s not the revival of downtowns as city centers (they are being revived, but lack the cultural dominance they once had), it’s the complexity of in-fill density, and whatever happens the development starts with where we are now (suburbs and big boxes and all), and it’s going to take a while to figure out what it will mature into. I think things like these “new urbanist” enclaves are immature — depending on how organically and vigorously they are allowed to mature, they might turn into something interesting; creating new centers seems like a positive thing to me. But of course there’s nothing that can be done right that can’t also be done wrong.

  • DJB

    “Forcing cities that aren’t great to go dense is just making everything worse”.

    Man, there’s a lot to unpack there, like what constitutes a “great” city, and what precisely is being made “worse” by density.

    Is the implication that Atlanta and LA aren’t great cities?! (I’m from LA)

    I think density has a lot to add to virtually all cities, if properly combined with a mixture of land uses: viability for cleaner transportation, and the associated health benefits for starters.

  • Thanks for the comments so far and thanks for the coverage. The point of the article is to highlight the fact that density alone isn’t going to solve our sustainability issues, and in some cases it actually makes things worse by exacerbating the “spatial mismatch” that is present.

    High-density developments on the fringe of metropolitan areas have the densities and even the mixture of uses to theoretically be a sustainable neighborhood. The problem is that the people that live there are more often than not commuting into the city, or to another suburb, to work or shop. While the people working in this development are coming from somewhere else. Adding more people to this disastrous dichotomy via higher densities is not the way we should approach sustainability.

    I am all for high-density developments and prefer to live in such environments. Unfortunately we need to get past the automobile and start creating communities that are truly sustainable by encouraging people to live, work and play within the same area…and when they need or want to go elsewhere there need to be high quality transit options available.

  • DJB

    Doesn’t this get to the chicken and egg issue of density and transit? You need transit to support density and you need density to support transit. We can’t use the absence of one as an excuse to block adoption of the other, since they need each other to survive. You have to start somewhere.

    All regions have a “spatial mismatch” of people living at some distance from their jobs. This is true even within Manhattan. Density improves the odds of having a close-by job, sets the stage for better transit, walkability and bikeability, and, in the short run, increases traffic congestion, which reduces the time disadvantage of cleaner transportation.

    NYC wouldn’t have such a high transit ridership rate if it weren’t such a pain in the ass to drive through. So why shouldn’t we try to make it harder for people to drive in other places as well? This incentivizes people to locate themselves closer to work, which reduces VMT.

    True in New York, true in LA, true in Atlanta.

  • “I think density has a lot to add to virtually all cities, if properly combined with a mixture of land uses: viability for cleaner transportation, and the associated health benefits for starters.”

    The point is, if you have a truly complex fabric of land use, do you even need density after all? Is it better to take mass transit for hours in a huge metropolis than to drive five minutes around the neighborhood?

  • AlexB

    If a city becomes dense, highways can’t support the transportation requirements. Faster, higher capacity transit needs to be constructed to support the population. Atlanta and LA have built some decent transit lines, but not nearly enough. This isn’t rocket science, it’s just very expensive and no one wants to pay for it. And, just because you build it, doesn’t mean you are going to make everybody’s life happy and easy. New Yorkers have the longest commutes in the country, but the only reason people ride them is because they are still faster than cars during rush hour. Let’s face it, LA should have had a mass transit line from Santa Monica to downtown decades ago, and numerous radial lines by now. It’s not the fault of density, it’s the fault of the politicians.

  • mfs

    Interesting idea, but I think you need a different term to describe this, such as “high-density sprawl”, instead of spatial mismatch, which is widely used to describe the mismatch in the labor market between labor demand (low-skill jobs) in the suburbs and labor supply (low-skill workers) in the center city.

  • What makes a “great city” is hugely dependent on culture. I once lived in a small city in Germany (Würzburg) that–like most German cities–was not terribly dense, but nevertheless offered an easy life without a car. Medium density can offer a car-free life in Germany; empirical evidence suggests that it cannot do so in the United States. A 30-story high-rise in a suburb which prohibits mixed uses might as well be five square miles of tract housing.

  • DJB

    It’s true there’s more to alternative transportation than density. In the small college town of Davis CA (population 60,000), something like 15% of people bike to work and the density is less than 6,000 people per square mile (2000 Census).

    In countries with higher transit ridership rates, you wouldn’t need as much density to support quality transit because a higher percentage of the people in an area are riding.

    In most U.S. cities, transit went into a death spiral a long time ago and at best is slowly recovering. Underfunded transit agencies that have low ridership because of culture and urban form are forced to offer infrequent service. Even with frequent service, transit is generally slower than all but the most traffic congested driving.

    When I look at the LA-area suburb I grew up in and ask myself why damn-near everybody drives damn-near everywhere in that particular neighborhood the answers are clear: there’s nothing much within walking distance, there are few bike lanes, and the (local bus) transit is slow and infrequent. When this is your starting point, it’s hard to argue for better transit (“you want to raise my taxes to build something nobody will ride?!”). If there were more density, more nearby businesses could be supported and better transit could be supported. Slowly but surely, the mode splits (AND average LENGTH of vehicle trips, would start to change for the better).

    Also, with density, you can start talking about charging for parking, which reduces vehicle use.

  • DJB

    By contrast, the neighborhood I live in now is the densest one in the city of Los Angeles. I can walk to supermarkets, restaurants, shops, parks, etc. Every major nearby street has frequent bus service (including some limited stop lines). I can walk to two subway stops. My building was built before off-street parking requirements and I’m doing all of this WITHOUT A CAR. My rent is affordable by city standards. All of the readily available parking in my neighborhood you have to pay for.

    I commute a few miles by subway to work, and a few miles by limited-stop bus to school.

    Density and mixture of land uses works. I’m living it, in LA.

  • Logan Nash

    I certainly agree that neighborhoods need to feature amenities that are in walking distance wherever possible, but even in the most urban neighborhoods, people are very often traveling to other areas to work, visit, or play. The reality is that we live in a highly mobile society, and we need to funnel as many of those inter-neighborhood trips into efficient transit as possible rather than sweat about the fact that they’re happening at all.

    I think the issue with this “high-density sprawl,” as one commenter called it, is the form and land use doesn’t accommodate walking or transit. Density is neutered with bad connectivity and poor design. That’s also why I don’t quite understand the potshot at New Urbanism. A high-density sprawl place like Tyson’s Corner is a mess right now, but with the Silver Line coming through in a few years and some “new urban” redesigns, it could very well become a viable urban area. I’m sure some people will live there and work in DC and vice versa. Drivers may even come and go to shop. But as long as residents and visitors are taking advantage of transit and walking-distance amenities, it would seem like a good case study for the potential to retrofit these dense suburban areas. As others have pointed out, trying to accomplish such a feat in a low-density suburban area would be much more difficult.

  • No potshot was intended for New Urbanism. My comment about new urbanism was critiquing the many fringe developments that claim to be a “lifestyle community” or “new urbanist development” just because they might meet a few of the new urbanist principles generally.

    I said to be “wary” of such developments if you’re looking for a truly sustainable neighborhood, because the use of “new urbanist,” “lifestyle center,” and/or “master planned community” has been overused to the point of meanings of those terms being dulled. It’s kind of like ‘greenwashing’ for planning.

    Once again, thanks for all the great discussion. Lots of great debate and this is obviously an issue that needs to be worked out in contemporary planning and urban design so that we are sure we’re getting it right when it comes to creating sustainable communities.



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