WABA designing a regional bike lane map to inform a more equitable network

Across Washington, D.C., and its bordering counties in Virginia and Maryland, the data on bike facilities and who has access to them can be awkward to piece together. The region is blessed with scores of miles of bike lanes and trails, up from very few in 2000. But when D.C., for example, says it has “75 miles of bike lanes,” what exactly does that mean for its residents?

This lack of clarity is what the Washington Area Bicyclists Association is seeking to address with its ongoing project to map every bike lane and trail across the D.C. region. The map – available in an early version here – currently includes geographic buffers around each facility, demonstrating how much of the region is within one mile of a lane. Ultimately, WABA would like that one-mile coverage to include safe biking routes for every resident in the region.

Presenting at the latest Transportation Techies meetup, WABA deputy director Nelle Pierson explained that the growth of bike lanes has not been balanced throughout the region. Neighborhoods where people have the time, connections, and resources to lobby for safer streets have historically received bike lanes, cementing the safe-biking network mainly to communities with privilege. A map that captures every lane will help WABA see where lanes are most needed and advocate for more equitable planning, helping bring bikeable streets to communities long deprived of them.

Coding group DCFemTech has been building the map, an idea that originally began at a two-day hackathon. “We quickly realized we actually needed months, not days, for this,” said presenter Alexandra Ulsh of the DCFemTech coalition.

The map itself uses lane data provided by D.C., Alexandria, and Prince George’s, Montgomery, Fairfax, and Arlington counties, but these all had to be reworked into a standardized style. Arlington-based bike advocate Chris Slatt, who helped unify the code styles, also explained at the meetup that the data raised questions for the overall purpose of the map.

For example, many jurisdictions classified small, 50-foot segments of trail leading into public parks as bike lanes. Should those count toward the lane coverage goal? What about marked sidewalk trails, or on-street lanes along fast-moving highways? Google Maps might include these, but they don’t help protect bicyclists or connect them to other networks.

Disconnected lanes

Would these trails in PG County help more people bike comfortably?

Beyond creating just a mapping-design problem, DCFemTech and WABA have to grapple with the question of what kinds of facilities lead them toward their end goal of safety and inclusivity, and how the map communicates and informs that.

Ulsh explained that the next steps are to add to the usefulness of the map. Adding population data will allow WABA to see who would benefit from future bike lanes, while filters will let users compare the efficacy of different types of bike infrastructure. And, in the spirit of most Transportation Techies presentations, the project is looking for more insight and help from interested civic coders.

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Excellent Chris, thanks!


King St. in Alexandria has some new bike lanes that aren’t reflected in the data. They put lanes down last year between the King St. metro and Janneys Lane –


And just recently put down new bike lanes on King Street between Jannneys Lane and Quaker lane, which are not on Google Street View yet.



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