How Much Walking Should You Do in a Walkable Neighborhood?

Walkability is a current planning trend that has implications for public health, traffic, land use planning, zoning, parks and pretty much everything we like about cities. All else equal, cities should favor more walkability over less walkability. Too often planners and urbanists narrowly define walkability as the ability to walk to places where they like to spend money*, and we should think more broadly about what walkable means for all types of folks, but in most cases more walking is better than less walking.

Say you live in a walkable community where you can do most of your errands on foot. How much might you walk on any given day? How much should you walk? Paul Krugman weighed in on this question on his blog. He notes that he walks about 15,000 steps per day, and this is "fairly easy to do." Since most people take about 2,000 steps per mile, he's covering about 7.5 miles daily. This is hard to do!

I posit that if you are walking 7.5 miles daily to go about your business you are not in a walkable community. Mabe farmers and ranchers cover that kind of ground, but at that distance your daily activities are too spread out for easy walking. That distance covered daily is getting close to the hunter-gather period where humans walked 3,000-4,000 miles annually.

An realistic pace for walking is about three miles per hour. This means that 7.5 miles is about 2.5 hours of travel per day, not including subway, bus, taxi, etc. It is certainly doable, but not simply by going about your business. You have to want to do it, and be able to afford to do it. Walking is a leisure good if your income is high enough. You can buy more enjoyable and slower travel and work a bit less. Most people don't have this option, however.

But how much walking is the right amount for a walkable community? I'm not sure, but one place to start is with established travel time budgets of around 90 minutes of total travel per day. This suggests walking about 4.5 miles daily, which is less than the doctor recommended 10,000 steps.  I'm not sure this is right or wrong (it is probably too high as carrying things while walking or traveling with children limits how far and how fast you can go), but a good place to start when evaluating walkable communities. People should be able to take care of their daily business by walking less than five miles per day.  If you use transit and live and work within 1/2 mile of your stops, then your commute includes two miles of walking. As the average person takes less than four trips per day total (Table 3 in this summary of NHTS data, and I realize that national data may not accurately reflect trip totals for denser areas) it seems unlikely that a couple more trips will lead to a few more miles, unless your destination are really far apart.

In sum, to make a community walkable it must have lots of things close together. The closer together these things are, the fewer miles traveled it takes to get to them. So the most walkable places are those where people can access the most while walking the least. If you are walking 2.5 miles per day for all of your activities--which is about what I average about forty blocks north of where Paul Krugman lives (somewhere on the Upper West Side as I understand)--then walking places is easy.

Since each mile is associated with about 100 calories burned, we should also temper our expectations that the marginal increase in walking will offset the increase in calories recently seen. Five miles daily is not enough to offset fancy coffee drinks, sports drinks or even eating out a couple of times per week.

So walking is good and we should encourage more of it through design, mixed uses and street redesign. We should also keep in mind that too much walking suggests that our communities are not actually that walkable and people walk a lot because they can. To be truly walkable people should be able to reach all of their destinations without walking far. Ultimately, however, if we really want people to walk more the best thing to do is get everybody a dog.




*Central Park is one of the best places in Manhattan to walk, but for the most part you just walk about and enjoy your company, the trees, turtles, an occasional bird, etc. Central Park is not a great place to walk because you want to have lunch at the Boathouse. Fancy people take a shuttle there.

Some Thoughts on City v. Suburban Growth

Source: WSJ (Linked below)
Lots of media outlets are picking up the story first reported in the Wall Street Journal that cities are growing faster than suburbs. See here, here, and here for samples. A few things about these data that suggest we should interpret the results with caution. First, these are growth rates, not absolute numbers. Because central cities make up a minority share of regional population most population growth--by a lot--is happening in the suburbs. Consider Atlanta, the second fastest growing city compared with its suburbs according to the chart at top. Atlanta has 432,427 people as of July 2011 and grew at 2.4%. The suburbs have 4,926,778 in July 2011 and grew at 1.3%. Here is the data source. This means that the metro growth was 73,361 for the year, 10,135 settled in Atlanta and 63,226 settled in the suburbs. In percentage terms, 14% of the growth happened in the central city and 86% happened in the suburbs. That doesn't suggest a sea change in attitude.

For most of the metros, the difference between city growth and suburban growth is so small I'm not sure that the difference is statistically meaningful (see the table at the data source above). 2011 are estimated data, and there is an error term associated. Perhaps all of the differences in growth rates are significant, but they have not been tested yet.

There are also large variations by region of the country and metropolitan area, and there does not seem to be any obvious and coherent trend. The headline claim is that more than half of metro areas saw one year growth rates in central cities higher than for suburbs. That means about half saw central city growth lower than suburban growth. In addition, many of the faster growing central cities are growing at essentially the same rate as their suburbs for the one year period in question.

There very well may be a shift in preferences and behaviors happening, and I suspect there is because preferences and behaviors are always changing. I just don't see that the stories highlighted here provide strong evidence that a large shift happened in 2010-11.

Lastly, let's look at how some central cities that have received nice press about robust growth fared. Here is my post from May 4 titled "Can We Exaggerate the Significance of Cleveland's Downtown Population Gains?" and, yes, we can exaggerate the importance of a few people moving to downtown Cleveland. Cleveland shrunk by a rate (-.6%)greater than the rate its suburbs shrunk (-.3%). Cincinnati has also been celebrated recently (see here and here and here for a few examples). That's going so well that the city is declining while the suburbs are growing (see above graphic). I'm happy that many cities are doing well and growing. I hope the trend (if there is one) continues and expands. I'm just not sure there is any evidence of a broad trend yet.


***This post was updated to correct typos in the Atlanta data in the first paragraph.

My Letter to the California APA in Support of AB 904

The California Chapter of the American Planning Association opposes reform to minimum parking requirements as required under proposed legislation AB 904. You can read about the legislation here on Streetsblog LA, here is the text of the bill, here is a Market Urbanism post about this issue, another brief explanation of the bill, Curbed LA coverage, and a story from the California Planning and Development Report.

Here is support for the bill from the Infill Builders Association. Below is the text of my letter as sent:

June 23, 2012
Dear Mr. Snow,
I am writing to express deep concern about California APA’s opposition to reforming minimum parking requirements through AB 904. I have studied parking regulations as part of my research for over a decade, half of which time I was in California. It is without question that minimum parking requirements are an egregious failure of planning, and the California APA’s position seems to suggest that, despite decades of evidence to the contrary, they know precisely how much parking should be supplied. The California APA’s position is troubling, to say the least, and actually reinforces the circular logic that got our cities into such trouble in the first place.
Minimum parking requirements increase the cost of housing, increase the amount of land needed for development, and represent the single largest subsidy to drivers. I will not dwell on these effects as the California APA’s letter of opposition suggests that you are aware of the need for reform. Parking reform should be at the top of any planner’s priorities for building better cities. I do want to challenge some of your reasons for opposing AB 904, and show why your concerns are unfounded.
In the basic issues section and in the specific concerns section you are worried that the proposed reduction in required parking minimums is not based on data. To quote your letter:

“Page 4, S. 65200 (a).  It is not apparent how these parking minimums were determined.  They appear to be based on no specific data.  Of chief concern is the requirement for one parking space per thousand square feet of any non-residential project regardless of use.  Given that most jurisdictions use 3-5 parking spaces per 1000 square feet for uses that require the most parking, such as grocery stores, stadiums, park and ride lots, and medical offices, this assumes that up to 75% of those using the project would be using transit.  That is a huge leap of faith and one likely to detrimentally impact projects surrounding these facilities.”

 This quote suggests that existing parking requirements are based on something other than a huge leap of faith. They aren’t. No one knows the right number of parking spaces, and no one knows how many parking spaces are already built. Just because most jurisdictions require 3-5 spaces per 1,000 square feet does not mean they are correct. As a telling example of how supposed “correct” parking requirements have performed, consider that the amount of required parking built in the United States allows researchers to estimate retail sales by looking at images of parking lots taken from outer space. Remote Sensing Metrics, a company that specializes in counting the number of cars parked in commercial and retail lots using satellite images, correctly predicted that the 2011 holiday shopping season was going to be a success because 39 percent of parking spaces were occupied at shopping malls. We live in a world where 60 percent of parking spaces are vacant during good times. I do not see how this indicates that cities know how to set parking requirements. It does suggest that we build too many spaces. I agree that the proposed minima in AB 904 seem a bit convenient, but so are existing requirements. However, the proposed changes aim toward planning for people, building better places, and achieving a broad set of planning goals. By maintaining the status quo, the existing parking requirements make it easier and cheaper to drive.
 Another concern expressed is the definition of transit-intensive areas, and you suggest that only areas with existing transit service should be included. California is heavily investing in new transit systems, and these systems take a long time to plan and build. Reducing required parking now will make these areas better for transit when the transit arrives. Requiring lots of parking in areas where transit will be built will reduce the utility of the investment. We should build transit in areas that are not dominated by automobiles because those are the types of areas where lots of people will use transit! Lower required parking standards strengthen the relationship between transit and land use.
 Reforming parking policy is difficult, but also presents opportunities for building a new regulatory framework that supports good planning and flexibility for accommodating future needs and uses. Maintaining the status quo hampers California’s ability to pursue creative policies that are more equitable and economically viable and that promote vibrant communities. I hope you will reconsider the APA California position.
  Regards,
   David King
Assistant Professor of Urban Planning
Graduate School of Architecture, Planning and Preservation
Columbia University
  Cc:      Kevin Keller
            Sande George

Here is a link to the letter.

22 Years for a Traffic Light

As a follow up to yesterday's post about a 34 year campaign for minor changes to alternate side parking regulations, here is a triumphant story about the mere 22 years it took to get a new traffic light in Brooklyn. From the Brooklyn Paper story:

Williamsburg residents rejoiced when the city installed a traffic light at the intersection of Woodpoint Road and Withers Street this week — 22 years after neighbors first requested it.
“We’re really excited, we’ve been fighting for an extra light,” said Community Board 1 member Tish Cianciotta. “We’re meeting people in the street, and they’re saying ‘Thank god!’ ”

Cianciotta says she finally swayed the city after 2010 Census data proved the area has experienced a population surge and now needs streets that are friendlier for pedestrians.Cianciotta, her husband, Guido, and members of the Withers Street Block Association started pestering the city to slow motorists at the busy corner in 1992 — but officials swatted down their requests, nixing a 2008 push for traffic calming measures even though a police cadet died in a motorcycle at the intersection three years earlier.

 Another data point that suggests it takes a really long time to change policy in many cases. For meaningful reform to transportation and land use planning you have to play a long game.

Some Notes on the Quality of Planning Research

The American Planning Association just released a report that has a lot of bold claims about what Americans want from planning. See here for a representative story. These types of reports are released all the time, and usually the are little more than an opportunity to abuse the use of pie charts (which you should never use). This new report, called "Planning in America," abuses pie charts nicely but also makes a number of claims that simply sound like a bunch of baloney. For instance, there is a claim that 50% of Americans think that having transit available is a high priority for an ideal community (Finding 5). Then the following finding (6) claims that local bus service ranks as a priority for on 36% of respondents and local train service is a priority for only 21%. I don't see how you reconcile finding 5 with the results presented in finding 6. This calls into question the methodology used to collect the survey responses. Transit usage is sufficiently rare in the U.S. that there is pretty much no way that half of American adults (as claimed in the report) think transit is a high priority. I suspect the truth is closer to finding 6, where most American simply don't care that much about transit because the overwhelming majority of Americans never use transit. This isn't to say that people are hostile to transit, just that they likely don't spend much time thinking about it at all.

Back to the methodology, it is too bad that the methodology is poorly described, and what is described is weak. Here is all the report says about the methods:

This research was conducted in the spring of 2012. Collective Strength, an Austin–based firm specializing in outreach and communications, designed the questionnaire and performed the analytics. Harris Interactive, one of the world's foremost survey research firms, reviewed the questionnaire to ensure objectivity and fielded the study during the month of March 2012.
This survey was conducted online within the United States by Harris Interactive on behalf of Collective Strength and their client the American Planning Association between March 8-12, 2012, among 1,308 U.S. residents age 18 years or older. 

Online only surveys are potentially problematic, and unlikely to be representative of the overall population. More critically, the methodology explains precisely nothing about how subjects were recruited. This is a major potential error. An additional problem is that online surveys have a high level of attrition as the survey goes on.  This is a pretty long survey, and I doubt all 1,308 respondents finished the whole thing. Since the report relies heavily on meaningless pie charts and does not supply the 'n' for any chart or table we simply don't know how complete the responses are. None of the companies listed in the section have any additional details listed on their websites. When the APA releases reports like this they are assumed to be high quality, authoritative reports. "Planning in America" is not an example of good planning research, however.

Reports like this bother me in part because I teach planning research courses and would be distraught if any of my students turned in a report of this quality (without additional explanation, anyway). But the larger issue is that low quality research--whether it confirms or opposes your personal preferences--reduces the signal to noise ratio. Reports like "Planning in America" are noise that cloud our ability to understand critical issues and policy (the signal in this case). At the very least the full methodology should be explained, pie charts jettisoned and sample sizes included in tables and graphs. As for planning research, reports like this are why I argue planning education should focus primarily on numerical literacy and well-crafted basic research with descriptive statistics rather than advanced regression analysis. We should train planners to communicate with data rather than claim to be psuedo-econometricians. Many of the greatest failures of planning can be directly attributed to planners' inability to understand the fundamentals of quantitative data. (See here for an explanation of the most egregious example.) Reports like "Planning in America" make the situation worse, at least as currently presented. Let's not get excited about the claims made in it.

Beyond Segways: We Should Care About Mobility Scooters

When the Segway was introduced some people claimed that it was going to revolutionize personal transportation. That hasn't really happened, not yet anyway, but perhaps Segway was simply too soon to market. As developed countries grapple with aging populations and the number of people who are mobility impaired increases mobility scooters will grow into a large market segment. This means that planners need to think about how to accommodate these vehicles. 

A couple of weeks ago the Guardian ran a story about the trouble that mobility scooters are causing in the UK. One takeaway from the article is that while the mobility scooter industry is booming no one knows anything about usage:

The steady rise in sales of these vehicles is evident in their inescapable presence in shopping centres, rural town centres, and high streets all over the country. Weirdly, there are no industry statistics that give an accurate sense of how the market is growing, but the Department for Transport offers estimates, suggesting that there are around 250,000 to 300,000 on the road across the UK, four times the total five years ago of around 70,000. Mobility scooter shops have opened up in most medium-sized towns in the past decade (also offering specially designed armchairs and beds for frail and older people).
None of the suppliers will reveal their sales figures, but around 60-70,000 scooters are thought to be sold here each year. No other country in Europe is selling as many (with the possible exception of Holland, where bicycle use is very high, and the mobility scooter is seen as a bike replacement for older cyclists).
There has been a marked change in the way people use them. A decade ago these were products used only by very frail people; now manufacturers are designing new models with bench seats capable of carrying people up to 40st. "It's a cultural issue. People are larger and, dare I say it, lazier," an industry spokesman says (before deciding that he doesn't dare say it, and asking for his name not to be put to the quote). "People are using them as a mode of transport rather than public transport or a car."

So far the design of Segways and scooters is sufficiently dorky or utilitarian so there likely aren't that many lazy people who choose to ride one everywhere. But since the market is expanding so rapidly I expect that new designs will emerge that capture the attention of people. For instance, check out this new Honda Uni-Cub:


The Uni-Cub doesn't help mobility impaired people much, if at all, because of the lack of a back and other things. But maybe a cool design like this inspires otherwise healthy people to buy them in droves. It happened with those Razor scooters, so I don't think it's far fetched to imagine it might happen.

A larger issue is what planners need to do about, if anything. Can motorized scooters co-exist with pedestrians, cyclists and cars? Will our penchant for new and dedicated infrastructure for all modes lead us to create special scooter lanes? That seems like a bad idea, but I suspect the growth in mobility scooters--by choice or condition--requires that planners start thinking about how to incorporate these modes into the built environment.

Aramis, Part Deux: Dreams of a post-Kyoto Paris

The New York Times has a story about new designs for Paris' master plan.* The proposed changes to the transportation systems are amazing in their technological innovation and system complexity. The proposals are the result of President Sarkozy's challenge to rethink Paris as a post-Kyoto sustainable city.

The article claims that the architects and designers "forsook flashy imagery for a deep analysis of the city's diverse communities and the fraying tissue that binds them together." They still managed to get a couple of flashy pictures in the Times, and they apparently forgot to provide any of the "deep analysis." Nevertheless, they proposed lots of ambitious designs that include putting tracks underground and building parks on the reclaimed land, building a "hard" green belt that acts as an urban growth boundary, building a giant new train station and, of course, an elevated maglev train. (At least they didn't propose a monorail.)

I think all of the architects and designers (and the President, for that matter) should go back and read Aramis, or The Love of Technology by Bruno LaTour, in which he describes the unbelievably expensive and ultimately doomed attempt to build a new persoanl rapid transit (PRT) system under Paris. LaTour paints a picture of misplaced priorites and incentives, and ultimately a fruitless chase for far more revolutionary transport technology than was possible politically or financially. As LaTour put it, the Aramis project resulted in "the most expensive armchair in the history of technology." The New York Times thinks the current proposals are the most radical in decades, but Aramis was finally put to rest in 1987.


*The headline of the stoy is "A New Paris, as Dreamed by Planners." This is incorrect. It's as dreamed by architects and designers. There is a difference.