My bike commute is just under four miles and for over half of that, I ride on one of Portland’s many bicycle boulevards (now called neighborhood greenways by the City). It’s the most relaxing part of my ride (well, except for those 10 uphill blocks on the way home). I rarely encounter a car and rarely must stop. I get to enjoy the neighborhood sights – a girl balancing on a tightrope strung between trees, chickens in front of the elementary school, a “Pro-choice parking” sign put up by a resident – without the worry of people driving cars too close or turning in front of me. Or, of slowing down another person on bike behind me.

While my story is an anecdote, at Portland State we have developed a body of quantitative, statistically significant evidence that bike boulevards are a good thing for cities. I’m going to highlight those findings here. But first, in case you don’t know what a bike boulevard is, or you know it by another name (neighborhood greenway, bicycle street, Fietsstraat (in Dutch), traffic calmed street), here is the National Association of City Transportation Officials (NACTO) definition:

Bicycle boulevards are streets with low motorized traffic volumes and speeds, designated and designed to give bicycle travel priority. Bicycle Boulevards use signs, pavement markings, and speed and volume management measures to discourage through trips by motor vehicles and create safe, convenient bicycle crossings of busy arterial streets.

You can learn more about designing them from NACTO and in FHWA’s Small Town and Rural Design Guide (developed by Alta Planning+Design). The fact that bike boulevards are showing up in guides for cities, small towns, and rural areas is a good sign.

So, why should bike boulevards be part of every bike plan?

People ride more on bike boulevards.

When we did our first GPS-based research study of bicyclists, we made two simple maps, one showing where they rode and one showing the shortest routes between their origin and destination. One thing that pops out is the use of the boulevards in Southeast Portland, particularly the SE Clinton and SE Lincoln/Harrison routes that lead to the diagonal through Ladd’s Addition and over the Hawthorne Bridge. (Note that these data are from 2007, so the boulevard network was not as extensive as it is today.)

The maps tell a story, but there is more that can be done with such detailed GPS data. Joe Broach modeled the route choices the study participants made, thus quantifying the value (positive or negative) of the features along the way. People spend their time and energy to go out of their way (off the shortest path) to either use attractive infrastructure or avoid bad infrastructure. With this sample of 164 cyclists who made over 1,400 utilitarian bike trips, we found that cyclists preferred separated paths first, followed by bicycle boulevards. Since most of the participants made 2–3 bicycle trips per day, the findings also suggested that even confident cyclists prefer routes away from motor vehicle traffic. The riders showed no real preference for striped bike lanes; they offset the negative effects of adjacent traffic on busy streets, but cyclists were just as happy with a basic low traffic volume street.

Our second GPS study had 491 adults who were recruited from several neighborhoods in Portland as part of our Family Activity Study. Many of them did not ride a bike regularly, or at all, so it is a more representative sample than the first study. And, we found that their route choice preferences were very similar to the first study, with separated, off-street paths up top, followed by bike boulevards, with little or no preference for simple striped bike lanes (see figure below, Source: Broach, 2016).

Bike boulevards can get women to bike more.

Next, Broach used that route choice information to analyze the mode choice decisions of the 491 adults, who made over 13,000 trips (by all modes) that were a reasonable bike distance (7 miles). Now we could see that not only did people bike out of their way to use paths and bike boulevards, but that that infrastructure made prospective riders more likely to ride a bike on a given trip, particularly women. Having a bike boulevard to ride on substantially increased a woman’s odds of cycling, eliminating the gender gap between men and women in some cases. And, once again “simple striped bike lanes had no significant positive effect on the choice to bike beyond offsetting moderate traffic volumes, consistent with previous route choice findings.” Those findings are available in this article and Broach’s dissertation.

Bike boulevards may be healthier.

When riding outside (and inside for that matter), we’re breathing in pollution. As a cyclist, we’re often breathing harder and, therefore, breathing in even more pollution. It would make sense that the closer we ride to the source of that pollution – mainly motor vehicles – the more we are breathing in. In his research while at Portland State, Alex Bigazzi measured cyclists’ intake of pollution on a variety of route types. He found that cyclists along bike boulevards were exposed to less air pollution because of the lower traffic volumes and traffic calming. That, combined with fewer stop signs, means that cyclists breathe in fewer pollutants.

Broach and Bigazzi used our GPS data from the first study, combined it with the air pollution exposure and inhalation data, and found that the shortest path bike trip is usually not the one that will minimize pollution intake. Bike boulevards and multi-use paths often provided a cleaner, healthier route, while those striped bike lanes sometimes drew cyclists to a more polluted route.

My colleague Jenny Liu and her doctoral student, Wei Shi, looked at the relationship between residential property values and bicycle infrastructure in Portland. They found that the density of “advanced” bike facilities nearby (defined as protected bike lanes, buffered bike lanes, and bike boulevards) was associated with increased property values (based on sales data) for single- and multi-family homes, and that proximity to such infrastructure was also associated with higher single-family home values. Discussing increasing home values at a time of an affordable housing crisis can raise red flags, as there is some evidence of transit investments spurring gentrification and displacement. Cities need to consider a full range of policies that help ensure that our public investments, including bike infrastructure, support equitable development.

But what about protected bike lanes?

When we did the two GPS studies, there were no or very few protected bike lanes in Portland. So, we were not able to assess how that type of infrastructure affects route or mode choice. In a study of new protected lanes in five cities, using surveys of residents and intercepted cyclists along the lanes, we found positive effects on people’s stated comfort and safety and their stated frequency of cycling. And when we surveyed 3,000 adults living in the 50 largest metro areas in the U.S. and asked them where they felt comfortable riding, more than twice as many felt very comfortable in a protected bike lane than a striped bike lane. But, even more felt very comfortable on a quiet residential street, with the share going up a bit more when we described a bike boulevard (see figure below).

When I talk about bike boulevards, people often ask about the trade-off between a bike boulevard on a residential side street versus a lane on the main road where commercial activity takes place. Since that’s where people want to go, shouldn’t we build bike infrastructure there? Yes, most of the time we should. But it isn’t always feasible. And, most bike trips do not start and end on a major commercial street. Looking at all of the bike trips made by adults and kids in our Family Activity Study, 70% of the trip ends were on a local street, the type of street that could become a bike boulevard. About 20% were on larger roads (collectors through highways that allow bikes). Now, the lack of good bike infrastructure on many of those roads likely suppresses current behavior, and our sample was of people living on local streets. But, I suspect that for most people living in the U.S., they are starting or ending many of their trips on local streets, including their home, school, friend’s homes, etc.

Let me be clear, this is not an either/or debate. We need both bike boulevards on low-volume streets and protected bike lanes on busier streets if we expect to increase cycling rates significantly, along with bike signals, bike boxes, and other intersection treatments. And I’ve highlighted research from the places we’ve looked at. Work from Kay Teschke and Meghan Winters in Vancouver, BC found a slightly higher preference for protected lanes over traffic calmed streets. But, personally, if there’s a bike boulevard within a couple blocks of my destination, I may still opt for it over a protected bike lane along the arterial with my destination. On the boulevard, I may be more comfortable, not having to pay attention to the faster cyclists wanting to pass me or the inattentive pedestrians, and I’m more likely to see chickens, cute kids playing, and quirky yard art.

More resources and links

A 2017 TRB Workshop on Neighborhood Greenways

The City of Portland Bureau of Transportation’s webpage includes an assessment of their Neighborhood Greenways.

A Streetsfilm on Portland’s Bicycle Boulevards/Neighborhood Greenways

NACTO’s Design Guide

FHWA’s Small Town & Rural Guide

More on Alex Bigazzi’s current research

NEW: And, they don’t cause congestion.

Since I wrote this original post, we now have research that demonstrates that people driving cars on bike boulevards are not really delayed by the people bicycling. That work was led by a PSU graduate student, Jaclyn Schaefer, in collaboration with professors Miguel Figliozzi and Avinash Unnikrishnan. You can read more about it here.