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The "Rounding Error" Error: Taking Bikes Seriously as Urban Transportation

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Boston Globe columnist Jeff Jacoby’s piece last week arguing for the banishment of urban cyclists from the streets has received predictable and smart push-back from several quarters. Many of the obvious whoppers in the column (No, Boston’s streets, many of which were laid out between the 17th and 19th centuries, were not “meant for … cars”; yes, cyclists do pay their fair share for their use of the streets) have already been rebutted.

But there is a less-obvious error in the column that is also worth examining. According to Jacoby, “when it comes to urban transportation, bike riders play a trifling role – literally less than a rounding error.”

The impression one gets from Jacoby’s column is that the primary impact of bicyclists on the urban transportation system is to annoy motorists. But urban cyclists are far more numerous than Jacoby’s misleading statistics suggest. And even though the aggregate share of travel conducted by bike is small, the role of bikes in urban transportation systems is far from trifling – and is growing rapidly.

Let’s look at the numbers. Jacoby writes:

According to the latest Census Bureau data, more than 122 million people commute each day by car, truck, or van. Fewer than 900,000 bike to work. Do the math: For every cyclist pedaling to or from work, there are 136 drivers.

This is a misuse of statistics. In looking at the role of bikes in “urban transportation,” Jacoby cites national figures that include not just cities, but rural and exurban areas as well. According to the same Census Bureau report Jacoby cites (PDF), cycling accounted for 1 percent of all commutes to work in the nation’s 50 largest cities from 2008-2012, compared with 0.6 percent nationwide.

In many cities, the share of bike commuters is even higher  -- in Boston, it stood at 1.7 percent for the 2008-2012 time period, and reached nearly 2 percent in the very latest 2013 data. The Census Bureau’s Census Explorer website allows one to view commuting statistics down to the Census tract level. In specific Census tracts in Boston, Cambridge, Somerville and Brookline, the share of bike commuters exceeds 5 percent, and in some cases, 10 percent. Bicycle commuting in many of these tracts has increased dramatically since 2000 (see below).

Bicycle Commuters by Census Tract, Boston Area, 2013

 

Bicycle Commuters by Census Tract, Boston Area, 2000

 

Moreover, Census Bureau data have long been known to undercount cyclists, with researchers in Minnesota finding that Census counts there understated the share of trips taken by bike by a factor of two to three.  The Census only registers those modes of commuting used most frequently and for the greatest distance. So, if you commute to work by bike once a week, or ride your bike to a commuter rail station, you don’t show up in Census figures as having used your bike at all. In addition, the Census only tracks work trips, not trips to school, for running errands, or for other purposes, which actually account for the majority of daily travel.

Regional travel surveys, such as the one conducted in Massachusetts in 2010-11, shed light on the bigger picture. In Greater Boston,[1] which includes many suburbs where bicycling for transportation is less common than in the urban core, about 1.5 percent of all trips occur by bike. Given the rapid increase in bicycling, there is little doubt that that figure is higher now.

But what about the busy urban streets on which bicycles apparently don’t belong? The number of cyclists using those streets is also far from trifling. According to the city of Boston’s (largely unscientific) annual bike counts, several major thoroughfares in the city see 1,000 bicycle travelers a day or more. City-wide in Boston, an estimated 79,000 trips are taken by bike each day – double the number of seven years ago.

Those bike trips are playing an important role in the urban transportation system. Major institutions have come to rely on bicycles as a way to provide access to employees and patrons without adding to local traffic congestion or necessitating costly expenditures on parking structures or other accommodations for solo drivers.

At Boston’s fast-growing and highly congested Longwood Medical Area, which is currently adding to its stock of more than 3,000 bicycle parking spaces, more than one out of every 10 workers uses a bike for at least part of his or her commute, according to a 2013 survey by the MassINC Polling Group. (PDF) Increases in biking, walking and transit use have contributed to the area reducing the number of drive-alone commuters by 13 percent over the course of a decade. (PDF)

And at Harvard University’s Cambridge campus, the ratio of bike to car commuters is not Jacoby’s 1:136 but rather 1:1. The university reports that more of its faculty and graduate students bicycle to its Cambridge campus than drive – either alone or in a carpool. (Transit is the most common mode, followed by walking.) (PDF)  There as well, the share of drive-alone commuters has been falling steadily in recent years.

Bicycling is also helping to extend the reach of the transit system, especially via the Hubway bike-sharing program. The second and third most popular sites in the Hubway network are at Boston’s North and South rail stations. These beautiful visualizations by Ari Ofsevit show how Hubway helps riders arriving at the stations make first and last mile connections to work and home. City bike counts suggest that Hubway is an especially popular option for reaching the burgeoning South Boston/Seaport neighborhood, supplementing the area’s lackluster transit options.

Bicycling in many cities, including Boston, is no longer a “trifling” part of the transportation system. It is a key tool for addressing major transportation challenges, and one that is growing rapidly. Forward-thinking cities around the country and around the globe are improving bike infrastructure because they are coming to recognize bicycling as a healthy, affordable, efficient, eco-friendly and fun way for people to get around.

Sadly, Jacoby’s column plays into the increasingly tired culture war rhetoric of bikes vs. cars. We need to move beyond that debate toward a more mature conversation about how to address transportation needs in ways that bring the greatest benefits to all transportation users, city residents, and our metropolitan areas as a whole. For Boston and for other cities that are experiencing a resurgence in population and economic growth, bicycling is likely to be a big part of the solution.

 

    

 

[1] The area covered by the Boston Region Metropolitan Planning Organization