How safer biking infrastructure works for women: quantifying the impact of protected bike lanes on accessibility across gender

Haynes Bunn
Sep 30, 2019 · 6 min read

As a woman and a long-time bike commuter, I’ve always been curious about how I experience being on the road differently than others. Unfortunately there are good reasons to think that my experience might be different simply because of my gender.

We already know that gender has a big influence on people’s likelihood of cycling: In the US, women on average take just 24% of all bicycle trips, despite taking about half of all trips using other modes of transportation. Similarly, research in the UK has found that women are about half as likely to cycle as men.

Why? Research suggests that safety while cycling (actual and perceived) is likely a major factor in explaining this gap. One example of safer infrastructure that is growing in usage is protected bike lanes: in 2018 there were over 500 protected bike lanes, an almost two-fold increase since 2016, according to People for Bikes.

But despite some recent progress, we have a long way to go, and if we’re going to make the case for safer infrastructure, can we prove that it actually works in addressing the accessibility gap in cycling?

Following is some research I presented earlier this month at the Transportation Research Board’s 6th International Conference on Women’s Issues in Transportation that attempts to quantify the impact of safer infrastructure across gender and illustrate whether women respond differently to this infrastructure than men.

Data

For this study, I looked at bike lanes in three cities:

  • Market Street and JFK Boulevard in Philadelphia, which both had protected bike lanes installed between 15th and 20th (traveling eastbound on Market and westbound on JFK)
  • East Cota Street in Santa Barbara, which had a lane installed in February 2018
  • 2nd Avenue in Seattle, which had its first protected bike lane installed between Pike and Yesler in September 2014, and was then extended from Pike to Denny in February 2018

To complete the study, I created three Strava Metro datasets for each city, built to an Open Street Map basemap: one of total activities, one of activities completed by female riders, and one of activities completed by male riders. Gender is self-reported in the Strava app to participate in specific leaderboards and statistics, but is not required.

Findings

For this post, I’m going to focus on the results from the Philadelphia analysis. Stay tuned for future posts about the Santa Barbara and Seattle findings.

Market Street

First, let’s start with Market Street, a plastic bollard and parking protected bike lane, which opened in June 2018.

Market St (purple) and Chestnut St (pink). Map © Mapbox © OpenStreetMap

For this street, I used Chestnut Street, a parallel street a few blocks away, to compare volume and usage. Chestnut Street has fewer lanes of traffic than Market and includes a bus/bike only lane.

Before the implementation of the protected bike lane, women had a higher volume of activities on Chestnut Street, as the first chart below shows. (The anomalous spike in activities in July 2017 is due to the Irish Pub Tour ride.) However, a few months after the June 2018 opening, the volume of women on Market Street started to surpass that on Chestnut for the first time.

There was no observable change in behavior by male riders. You can see the volume of usage by male riders was pretty similar on both Market Street and Chestnut Street.

JFK Boulevard

JFK Boulevard had a similar bike lane to the Market Street bike lane traveling in the opposite direction, also installed in June 2018. For comparison purposes, I used Arch Street. Similar to the comparison above, Arch street has fewer travel lanes than JFK Blvd.

JFK Boulevard (purple) and Arch Street (pink). Map © Mapbox © OpenStreetMap

Interestingly, unlike the Market St scenario, before the bike lane installation on JFK, Arch Street had consistently seen higher volumes of bicycle activities, regardless of gender, signaling that both men and women were not preferring to bike on JFK.

After the installation of the lane, Arch Street remained slightly more popular among both genders based on pure activity volume, although the gap in usage closed for both genders. This is encouraging because it suggests that in certain cases, safer infrastructure can benefit all riders.

Nevertheless, we do still see a disproportionately positive impact of the infrastructure on women on a percentage basis: the percentage of activities completed by women on JFK Blvd has been increasing, up to nearly 40% of bike trips in January 2019.

I found these examples interesting both from the perspective of showing the impact of safe infrastructure and in establishing an easily adaptable framework for assessing the impact of bike infrastructure by gender, and I’m excited to explore more with the public agencies that Strava Metro partners with.

Limitations

Strava is of course a sample of the total cycling activities, and therefore this study is based on a subset of the total cycling population.

Additionally, the type of “protection” on these bike lanes is rather minimal: plastic bollards don’t provide physical protection from cars but rather serve as a visual cue to car drivers. This may affect the level of stress or perceived safety felt by cyclists.

Connectivity to other bike lanes may also play an important role in whether cyclists choose to use the infrastructure or not — cyclists are attempting to complete a trip rather than test infrastructure. The level of connectivity of these pieces of infrastructure was considered as part of this study.

Future Research

There are numerous opportunities for further research in this area. This analysis was completed in spring 2019, which meant that a full year had not yet elapsed since the opening of the protected bike lanes in Philadelphia. Additional study using data from summer 2019 will be key to see how the peak cycling season traffic patterns have been affected.

Furthermore, completing this same study at additional locations, especially those outside of the US that may have different styles of “protection” for bike lanes, will be key in understanding the magnitude of the impact from safe infrastructure.

Using other features available on the Strava Metro platform, such as origin/destination zones, individual street segments (instead of the full bike lane facility), and route choices may also provide additional insights into the different behaviors or cyclists across genders.

How does your city compare? Do you think people make different choices when biking for transportation in your region depending on their gender? Let us know in the comments — maybe your city will be the subject of our next study!

And if you haven’t been to the TRB Women’s Issues in Transportation Conference, I highly recommend it — It was an incredible four days of hearing about how women experience different modes and facets of transportation all over the world. For instance, did you know that airbags in cars were discovered to be more lethal for women than for men? That’s because the testing had been done based on the average size of men. Anyway…

Strava Metro

Let’s make active transportation accessible, safe and efficient for everyone.

Haynes Bunn

Written by

Customer Success GIS Engineer — Strava Metro

Strava Metro

Let’s make active transportation accessible, safe and efficient for everyone.

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