From Minneapolis, Evidence That the Census Undercounts Walking and Biking

Biking jumped 58 percent in the Twin Cities region between 2000 and 2010. Photo: Wikipedia
Biking increased 58 percent in the Twin Cities region between 2000 and 2010. Photo: Wikipedia

The U.S. Census is the most widely cited source of data about how Americans get around. It’s updated regularly and it covers the whole country, but it comes up short in a number of ways. The Census only asks about commute trips, and commuting only accounts for about 16 percent of total household travel [PDF]. What happens when you measure the other 84 percent?

Researchers at the University of Minnesota set out to design a better way to track how people move around the Twin Cities region, and one key finding is that walking and biking appear to be growing a lot faster than the Census indicates.

Image: Transportationist
Image: Transportationist

The UMN survey asked about 1 percent of the region’s residents to keep a travel diary, recording every trip. This resembles the National Household Travel Survey, a more detailed but infrequently-conducted cousin to the Census data on commuting, but the sample collected by the UMN team was much bigger. That’s especially important for measuring less prevalent modes of travel like walking and biking. The UMN study also provided more detailed information about people’s origins and destinations than the National Household Travel Survey.

The UMN team found that driving decreased in the region between 2000 and 2010, while biking and walking grew. Cycling rose over that period from 1.4 to 2.2 percent of trips. That’s about 190,000 daily trips, or a 58 percent increase. Meanwhile, walking grew from 4.5 to 6.6 percent of trips, a 44 percent increase, or almost three quarters of a million daily trips. Residents of the Twin Cities region typically make about 12 million total daily trips.

What’s especially interesting is that the share of biking and walking trips in the UMN survey is much bigger than what the Census indicates — about two to three times larger.

David Levinson, a UMN engineering professor and co-author of the research, said he expected the data to show a higher number of biking and walking trips because the Census examines such a limited subset of travel. But he didn’t expect the difference to be so large.

Levinson noted that the increase in cycling coincides with major local investments in biking infrastructure for the region. “If you provide facilities, you’ll get more users of those facilities — that goes for any mode,” he said.

The more detailed data Levinson and his team collected will be used by regional planners at the Metropolitan Council on forecasts to inform decisions about transportation infrastructure.

28 thoughts on From Minneapolis, Evidence That the Census Undercounts Walking and Biking

  1. It’s so obvious how much undercounting going on. And I think the U.S. Government actually doesn’t mind that. After all if they saw how dramatically different non-rush hour weekday modes of transportation differ from other times of day plus the weekends, they’d see how screwed up their funding models are.

  2. the SF bike count is out, and it only increase 1% in 2014 vs. 2013, yet 2014 driest and warmest year on record. this actually represents a drop in biking as a mode share per capita. why did we spend all that mony on bike lanes? was it just to crate gridlock for cars?

  3. Great report!

    I’ve long been a bit puzzled at the obsession with commute modeshare when there are so many other trips people make in a week.

    Commutes are mostly not the low-hanging fruit for converting trips to bike–it’s the 84% of other trips people make per week…the great majority of which are under a couple miles.

    Accordingly, it’s a huge fallacy to equate commute modeshare with trip modeshare in any given city.

  4. As the SFMTA mentions in the report, you cannot look at one year vs. another numbers and expect to get a meaningful picture of the rates of bicycle usage in the city. You need to look at long term trends, and they show that bicycling is up 206% since 2006. Since infrastructure additions have seriously lagged increases in numbers of people who ride bicycles, the city is only just catching up to this reality.

    As an aside, there is no data from SFMTA that suggest the introduction of bicycle lanes on city streets has impacted car traffic. What is the more obvious issues for the city are double parking and construction zones that narrow the existing alignments, and the increase numbers of people who are driving in the city due to the larger population and job growth.

    Besides, what do you care? You walk 20,000 steps a day in the city. Sounds like you just enjoy taking pot shots at people who ride bicycles more than anything else.

  5. you know, i actually ride my bike alot too, just not for commuting. I mostly ride over the GGB and into marin for long rides and do it for recreation. I just don’t like the fact that city policy has been taken over by a very vocal minority that is pushing everything bike related. We have to remember that only 3.5% of people commute by bike, and it seems that its now growing at 1%/yr. the share of voice by bike advocates is much too large taking into account the extremely low numbers of cyclists. there needs to be some balance. the city is going overboard to bend to every whim of cyclists. its just too much.

  6. For the last 100 years we’ve been building out car infrastructure at the expense of those who walk and ride bicycles. I’d hardly call what has been happening in the last decade anywhere close to bringing “balance” back to our streets.

    I get your number now, though. You walk 20,000 steps a day. You also ride for recreation in Marin on your bicycle. You’re what’s referred to in the demographic community as a “Strong and Fearless” rider. Sounds like you don’t care a whit whether anyone else rides bikes in the city. In fact, I’ve venture to guess that you think there should be fewer people on bikes riding around as they probably get in your way and don’t ride “correctly”.

    The thing is, though, because of the dominance of car infrastructure in the city, you’re going to find it harder to get around as you get older. Did you know people in their 80’s riding bikes in the Netherlands? Kids in middle school ride independently to their schoos? And no, it’s not because there aren’t any hills. It’s because the infrastructure supports older people and younger people riding. So, despite your current fitness there will come a time where you’ll have to hang up the bike because it’s too dangerous. And where getting hit by a car crossing the street will become more of a certainty, because you can’t move so fast. But sure, right now, you don’t think anything needs to change. But, in a few decades, you might think a bit differently.

  7. And let’s not forget that multi-modal commutes are counted as the mode with the longest distance, not time. I bike for 30 minutes and ride a train for 15 in my daily commute, but I’m counted as a transit commuter since the train covers more distance than I do on the bike.

  8. There are many, many, many problems these days with drawing conclusions about travel mode share through telephone surveys. The San Francisco Metro Transit Authority’s Transit Decision Survey is a good example of deeply flawed methodology that brings in bad data which then contributes to bad decision making. The survey performed by the University of Minnesota was far more rigorous and brought in better data.

    1) The SFMTA survey is based on an extremely small sample size. In San Francisco, the survey company was only able to get interviews with 375 SF residents and about the same number of out of county residents. In contrast, the Minnesota survey got data from 1% of the entire population of the Minneapolis region. If the SFMTA had done this, they should have gotten data from over 8000 San Francisco residents alone.

    2) The SFMTA survey was based on *who answers their phone from an unknown number*. This is becoming an ever dwindling set of Americans, and not a particularly random subset. Although I might be glad to participate in a travel mode share survey, I don’t answer my phone from anyone I don’t know because even though I am on a do not call list, over 90% of the calls coming into my phone are telemarketing (even, I’ve found, if caller id says “survey”). There is no way telephone surveys these days can pick up a random sample of the population. They pick up a sample of people willing to risk answering telemarketers.

    3) The SFMTA survey asked people a lengthy set of questions to discern their travel choices. I would be surprised if the survey took under ten minutes. Again, their survey sample will include only the people who have ten minutes available and the patience to go through the lengthy process. Because of the methodology, it is especially likely to undercount walking trips because people are most likely to forget short trips they might have made walking. The University of Minnesota data was pulled from travel diaries that people kept for one day. Travel diaries are performed more at one’s leisure, and since you get the diary ahead of time and know you’ll be recording your trips, your are more likely to remember all the trips taken.

    4) The SFMTA study did not count the travel choices of anyone under 18. The Minnesota study did.

    5) The SFMTA San Francisco travel mode number is weighted roughly 3/4ths San Francisco residents and 1/4th out of county residents who take trips into the city. This is naturally going to weight the mode share number against bikes, because very few people from out of county bike into the city. (If they take BART or Caltrain and then bike, the trip will count as transit.) While it is useful to know the mode share of people not living in the San Francisco on their trips to the city, you can’t draw conclusions about the travel activity of people who live inside San Francisco from this data.

    While I laud the SFMTA for trying to collect annual data, when the methodology is based on a telephone survey, the resulting data is flawed enough so as to not be able to draw conclusions about much of anything, except how the biased sample’s behavior might change from year to year. The University of Minnesota’s approach of a much, much, much larger sample size and using travel diaries is far more valid and useful.

  9. Another multimodal transit + bike commuter here!

    Bringing my bike solves the classic Last Mile problem in addition to opening up to 5 bus lines + a ferry viable for my commute. This introduces much-needed transit redundancy for me within the rigid confines of an agency (Golden Gate Transit) that typically only has hourly service per bus line and even fewer per ferry. Oh yeah, and still no real-time tracking.

    The most common trip I do involves a bus ride of 25 minutes + a bike ride of 15 minutes, roughly a 60/40% split. And of course the bike makes the transit viable in the first place.

    Yet it’s funny that because I spend roughly 10 more minutes on transit than the bike it would be counted as a transit trip only.

  10. NYMTC, a regional group in the NYC area, put together a travel survey a few years ago.

    Full time employed persons made an average of 4.1 trips per day, 2.1 were work trips. I wonder if part of the reason for the focus on commute trips is people thinking of the trips they make, and the people in charge travel mostly for work, and see their commute to the office as having much more economic worth than their walk to grab food at midday?

    Also, walk/non motorized trips out numbered transit trips. Biking was just a small share of that though.

  11. Netherlands is a tiny country with little global importance. Amsterdam peaked as a global player about 4 centuries ago. It is now a tourist town known for weed prostitution and biking. We are a global economic player and #1 tech city in the world. If we really want to reduce private cars , then we need to think in a more transformative way. Our public servants are 20s behind the think of our private enterprises. We are on of the few world cities without a usable subway system. Uber and the private shuttles are thriving because the city and region have not addressed transportation. We are not going to bike our way out of it because so few people are biking. Doubling commute mode share from 3.5 to 7% may never happen. Portland has stalled out below 7% after years of growth and SF is starting to show those signs as well. Private enterprise will have to save us because the city officials are stuck in the 80s. I’m not ant-bike. I’m anti- focusing too much attention on such a tiny mode share when the big thing that needs to be tackled is decent public transport. We are beyond Amsterdam. We need to be thinking bigger

  12. Not much of a surprise there. In much of NYC things are indeed close enough to walk. No need to take a bike. I tend to think shopping or entertainment or visiting trips now taken by car in the outer boroughs might be the low-hanging fruit for increasing bike mode share. These trips are typically only a few miles—well within what is considered biking distance.

  13. Yes non work trips are generally short. For trips originating in NYC outside of Manhattan median trip length overall was 1.2 miles in their survey. But the subset of trips to work was 4.1. It’s not just NYC though. Median trip length in queens is 1.5, same as Nassau. Westchester is 1.6. Retool surface streets to better fascilitate those short trips, which means slower speeds, shorter light cycles, and more frequent crossings etc…and more of those trips will be easier to make without a car.

  14. I think this will depend on the location in question, such as specific cities vs. suburbs or more bike-friendly cities (NYC, Chicago, Portland, Davis, San Fran, Twin-Cities) versus ones that historically have lacked any decent infrastructure for cycling (i.e. many cities in the south). I’m willing to bet that in some places, there are probably more people commuting to work by bicycle than for other trips like shopping, etc. Part of that may be due to lifestyle habits or practicality factors (grocery shopping frequency, willingness of family members or friends to also commute by bicycle, type of bicycle available, etc.). Most people in my city either commute with mountain bikes or road bikes that do not have any racks and thus can’t carry very much. At my university, I knew quite a few students and even professors who biked to work and sometimes for recreation as well, but none of them did any shopping or commuting to restaurants by bike.

  15. Jimbo, every heard of Rotterdam? It’s the largest port in Europe and the 10th largest in the world. Know where it is located? That’s right. To say that the Dutch aren’t a world player in trade and transportation just shows how out of touch you are with other countries.

    That being said, I share your frustration with the public transportation system we have in San Francisco, but let’s point out that we actually do in fact have a subway – ever heard of BART? And last I checked, it’s pretty usable and covers the East Bay and down to Milbrae. Sure, it’s doesn’t cover all the city, but that’s because our city doesn’t have the density to support a fully built out Subway system the way you need one in New York, Washington DC, or Boston.

    But, I don’t blame public officials – I blame the public who fight every change in San Francisco. I mean, MUNI can’t even remove a redundant bus stop without getting community push back. And the reason why we don’t have BART out through the Richmond has more to do with politics then anything else.

    The thing about bicycle infrastructure is that it’s cheap. It costs billions to build public transit, where it costs only low digit millions to build bicycle infrastructure. For most of the last decade, the city has been spending on order of 1-3% of it’s transportation budget on bicycle improvements. Arguably less money then there is mode share. Despite the fact that there has been a 206% rise in ridership over that period.

    As for private enterprise ‘stepping in’ to solve our transportation problems, I’m pretty sure that many would argue that Uber, Lyft, and others are performing a function that a robust taxi service would. You cannot possibly argue that it can replace a mass transit network like BART.

  16. on last point, im not arguing that uber, lyft or Leap will replace, but they are deffinitely supplementing where city run transportation has failed. More Leap buses and other companies will come online soon.

    Regarding BART, no I do not consider it as a usable subway for the city. It is mostly for suburb commuters to SF. the only people in SF who can use it to commute are those in the mission or glen park. it serves as a subway for 30 min from arguello to downtown. totally nuts.

  17. Where can I find the SFMTA info about bike traffic being collected via electronic counter.

  18. Honey, the SF bike count isn’t done via survey.

    Where does the article say anything about the SF bike count? You do realize where the “Twin Cities” are, I hope?

  19. We are not going to bike our way out of it

    No one has ever said one transportation solution is the end-all be-all, but do remember that every trip made biking, walking, and/or transit is one that could’ve been saddling the streets with yet another car.

    Imagine if all the people on bikes in this scene were instead in individual cars:

    because so few people are biking.

    Your argument is akin to saying the Golden Gate Bridge shouldn’t have been built because so few people were already swimming across it.

    When you build good infrastructure (such as that in the video above), higher ridership ensues.

    The paltry amount of infrastructure that’s been built for biking amounts to 1.5% of SF’s paved roads. SFMTA’s capital expenditures on biking have been about 0.48% of its budget per year.

    What *has* been built is usually subpar conventional bike lanes that get double-parked in or otherwise obstructed. No wonder most people take a pass.

    Doubling commute mode share from 3.5 to 7% may never happen.

    Especially with SF’s current glacial and outdated approach to bike infrastructure! Again, I wonder why so many people take a pass when this is what biking all too often looks like:

    Btw, remember that commute modeshare =/= trip mode share. SF has not stated specific commute modeshare goals, as far as I’m aware.

    We should be focusing on overall trips made within the city, not just the ~16% that involve going to and from work.

    Portland has stalled out below 7% after years of growth

    Despite its marketing Portland is not a real bike Mecca. Most of its infrastructure is still conventional bike lanes. If they exist at all. Remember, much of Portland still looks like this, even in the central core:

    Who’d want to bike there? Part III.

    the big thing that needs to be tackled is decent public transport.

    Better public transport is not mutually exclusive with better biking/walking infrastructure. All of the above, please!

    In fact, biking/walking infra is so cheap it’s effectively a rounding error considering what other infrastructure projects cost.

  20. Oh yeah, I almost forgot through my criticism to say, No matter the optics of this site, the content is fantastic. Good show.

  21. Excuse me, but Dutch exports value are over a 1/3 of all Chinese exports. Phillips, the electronics company, is Dutch, and so is the company Timex, to name two huge multinational corporations right off the top of my head, and I know that there are others. Rotterdam is still one of the world’s largest ports. The Dutch also have one of the world’s largest gas reserves of anywhere in the world. Look up the Groningen Gas Field.
    By the way, there is a Wikipedia article devoted to a list of Dutch Inventions and Discoveries over the years. The list is 116 pages long (I found this by going to the Wikipedia article, pulling up the print menu on my browser and seeing how many pages it would take to print the article). Here’s the url:
    The Netherlands was also a founding member of the EU. The Dutch Government is one of the most financially sound in the world; they are on an even better financial foothold than Germany., and they do have a positive account balance of >15,000 Euros per person.
    They also still technically have a government which oversees various former Dutch colonies as “Constituent Countries” (what exactly this means is not clear to me). It becomes very clear that the Dutch have been and still are of global importance.

  22. I forgot Shell and ING group. There are other very large ones, but they tend not to be the visible kind of company.

  23. Oh, and what the heck do you mean, “Without a usable subway system”? Bogota, Curitiba (in Brazil), Sydney, Melbourne, Auckland, Houston, Dallas, and Leeds (in the UK) all have larger populations that San Francisco, and they don’t have ANY subway system at all (not even an unusable one).

  24. Los Angeles has two Subway Lines serving 4 million people. San Francisco’s BART has more lines and coverage to serve fewer people. Hmm…

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