Mapping Seattle's Bicycling Future

By Josh Cohen April 26, 2010

Seattle Transit Blog's Adam B. Parast recently completed a fantastic study of Seattle and Portland's current and potential "bikeability" for an advanced geographic information systems class. The study weighed different factors like infrastructure and topography to score Seattle and Portland's bikeability, which Adam presents on color-coded maps.

The surface-level takeaway from his study is that Portland is currently better for riding and has more potential than Seattle.  Far more importantly, however, the study provides a data-driven foundation for shaping the direction of Seattle's bicycle-infrastructure planning and investments.

For the analysis of current bikeability, Adam looked at street connectivity, land use, bicycle facilities, slope and barriers (each weighted by importance). By those standards, Seattle's current bikeability looks pretty grim. If you look at the map above (or, click here for a high-quality PDF of the maps), you can see that Seattle has significant amounts of red (bad) and almost no green and blue (good). Adam says downtown's very low score might have been due to an error. The all-around low score is due in part to our many hills, of course, but a lack of substantial bike-infrastructure contributes to the low scores as well.

Though the study's analysis of current bikeability is bleak, the analysis of Seattle's potential is very promising. For potential bikeability, Adam only took into account the permanent factors: slope, street connectivity, and land use. As you can see in the second map, Seattle's city center scores very high, with pockets of good potential bikeability scattered throughout the city.

Adam draws two major conclusions from his study. The first: Seattle needs to concentrate on building bike infrastructure that connects its pockets of very bikeable areas. With the exception of the Burke-Gilman Trail there's little noteworthy east-to-west infrastructure. The story is even worse with north-to-south infrastructure.

Hills obviously play a huge role in this (there are few places in the city as flat as the Burke-Gilman or the waterfront). But some well-thought-out bike infrastructure would go a long way toward mitigating the hill factor. I suspect that if cars weren't buzzing past eight inches from their shoulders, people would feel more comfortable slowly chugging their way up hills in low gear.

Adam's second conclusion is that Seattle needs transit that meshes better with cycling. If people could ride from their homes to the light rail station or bus stop, take their bicycle with them on transit that they didn't have to wait half an hour for, then ride around an island of good bikeability like Beacon Hill, Capitol Hill, or downtown, it might increase their willingness to use a bike to get around. Not having to deal with parking downtown (less and less of which is free, according to my cranky colleague) is almost enough of selling point on its own.

The bikeability study isn't a blueprint for the future of Seattle's bike infrastructure, but it does provide an excellent framework to make informed decisions about where to spend our extremely limited transportation dollars. If you haven't already (and I'm guessing many of you transportation wonks already have), head over to Seattle Transit Blog and take a look at this excellent report.
Show Comments