less steep (%)

< 3

3 to 9

10 to 14

15 to 19

>= 20

more steep

How steep is it?

SteepStreets: Seattle

Exploring Seattle's topography through open data

Seattle is a city of hills; its history and its character are inextricably shaped by the contour lines of its topography. There's no doubt that to know Seattle's hills is to know the city. If you spend any amount of time here, you'll find that Seattle's hills are a central to how people here live, work, and play. Not only are there are a lot of hills in Seattle, but there are a lot of steep ones!

SteepStreets is an interactive map that invites you to explore Seattle's steepness through its >23,000 street segments. This interface is a fun way to get a sense of the "shape of the city" and provides a tool to appreciate the importance of Seattle's hills in shaping city life.

About the data

This project is powered by the streets dataset from the Seattle Department of Transportation (SDOT) which maps the city's street segments at the block level. The street "steepness" in SteepStreets is based on the percent grade (%). Note: 0% grade would be perfectly flat (a 0° slope angle) and a 100% grade is actually a slope angle of 45° (where "rise" is equal to "run" or where one step forward in the x-direction is equal to a step up in the y-direction).

A number of street segments have been filtered out from the dataset for the purpose of this project, namely those street segments that might have outdated data or those that no longer exist and streets that have either been manually verified to be stairways (as extensions of a street block) or those that are otherwise unnavigable by a bike (to be frank, I'm partly motivated to know what streets I might be able to ride up/down).

According to the data, the steepest street is located at Hillcrest Ave SW & 57TH AVE SW and has a grade of 47% but if you check the Google StreetView link, it doesn't look particularly steep. However, if you go over to SW Andover St & 57th Ave SW there is definitely some notable steepness. Zooming out, about 2% (~500) of Seattle's street block segments have a 15% grade or higher and about 20% (~2200) of Seattle's street block segments have a 7% grade or higher. In case none of those percentages mean anything to you, you can find some helpful descriptions linked here at TheClimbingCyclist.

This is hardly a scientific exploration but rather a fun side project. I hope you enjoy it!

Site seeing

Seattle's iconic hills are the gateway to city, mountain, and lake and ocean views and its major neighborhoods. Whether you're climbing to the top by foot or bike (or even car), summitting Seattle's steepest hills provides a palpable payoff in the form of breathtaking views and exhilerating descents.

I'm definitely not the first to seek out Seattle's steepest climbs and not likely to be the last. Here's some recent photos from some bike rides and walks up these steep streets:

E Columbia St & 37th St

E Terrace St & Randolph Ave


Made in Seattle with ❤ by Joey K. Lee (2023)

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