{"id":8749,"date":"2025-04-30T14:05:36","date_gmt":"2025-04-30T22:05:36","guid":{"rendered":"https:\/\/depts.washington.edu\/pactrans\/?p=8749"},"modified":"2025-05-27T13:18:39","modified_gmt":"2025-05-27T21:18:39","slug":"mapping-our-way-to-accessible-cities-via-ai-powered-crowdsourcing-a-look-inside-project-sidewalk","status":"publish","type":"post","link":"https:\/\/depts.washington.edu\/pactrans\/mapping-our-way-to-accessible-cities-via-ai-powered-crowdsourcing-a-look-inside-project-sidewalk\/","title":{"rendered":"Mapping Our Way to Accessible Cities via AI-Powered Crowdsourcing: A Look Inside Project Sidewalk"},"content":{"rendered":"
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Figure 1.<\/strong> Project Sidewalk\u2019s mission is to map and assess every sidewalk in the world via crowdsourcing, artificial intelligence (AI), and online map imagery. Above, a Project Sidewalk user labels a \u201csidewalk uplift\u201d as a surface problem, which poses a significant safety and accessibility hazard.<\/em><\/p><\/div>\n

\u201c<\/span>Using Project Sidewalk gave me a new perspective that I can use to help change the world.<\/span><\/i>\u201d – Girl Scout, Age 11<\/span><\/p>\n

\u201c<\/span>It is amazing to think that in just a few hours, users can label so many problematic sidewalks and validate others\u2019 work<\/span><\/i>\u201d – Wheelchair user<\/span><\/p><\/blockquote>\n

Sidewalks are more than just concrete paths; they are vital arteries of our communities\u2014connecting us to work, school, shops, transit, and parks. They are spaces for strolling, playing, dining, and commerce. For many, especially individuals with mobility challenges, accessible sidewalks aren’t just a convenience \u2013 they are lifelines, enabling independence, physical activity, and access to key services. Despite decades of civil rights legislation, however, many city streets and sidewalks remain inaccessible. As the United Nations notes, \u201c<\/span>[there is a] widespread lack of accessibility in built environments, from roads and housing to public buildings and spaces.<\/span><\/i>\u201d<\/span><\/p>\n

The Hidden Problem: Missing Data<\/span><\/h2>\n

The challenge isn’t just fixing broken sidewalks; it’s also that we often don’t even know where the problems are. Reliable data on sidewalk existence, condition, and accessibility features are surprisingly scarce. For example, in a sample of 178 US cities, Deitz et al. found that only 36 (20%) published sidewalk data, 18 (10%) had curb ramp locations, and even fewer included detailed accessibility information like sidewalk condition, obstructions, and crossing controls<\/span>.\u00a0<\/span><\/p>\n

This lack of data fundamentally limits how sidewalks can be studied in cities, the ability for communities, disability advocacy groups, and local governments to understand, transparently discuss, and make informed urban planning decisions, and how sidewalks and accessibility are incorporated into interactive map, navigation, and GIS tools. Imagine, for example, loading up Google Maps and being provided personalized pedestrian-based routing directions that avoids obstacles and meets your mobility needs.<\/span><\/p>\n

Enter Project Sidewalk: A Virtual Solution with Real-World Impact<\/span><\/h2>\n

This is where <\/span>Project Sidewalk<\/span><\/a> comes in! Developed by Professor Jon E. Froehlich and his lab at the University of Washington, with support from PacTrans, UW CREATE, and the National Science Foundation, this innovative tool is revolutionizing how we map and understand sidewalk accessibility.<\/span><\/p>\n

How? By harnessing the power of <\/span>crowdsourcing<\/b>, <\/span>artificial intelligence (AI)<\/b>, and <\/span>online map imagery<\/b>. Project Sidewalk allows <\/span>anyone<\/span><\/i> to become a virtual sidewalk explorer. You virtually explore cities via immersive imagery similar to a first-person video game, labeling sidewalks and identifying accessibility features or problems like missing curb ramps, uneven surfaces, or obstructions. Other missions allow users to validate pre-existing labels to ensure high data quality. See Figures 1 and 2.<\/span><\/p>\n

For each identified sidewalk feature or obstacle, users assign a severity score, add descriptive tags, and can even leave detailed notes. This data is then used for:<\/span><\/p>\n

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  1. Creating powerful new <\/span>interactive visual analytics <\/b>of urban accessibility.<\/span><\/li>\n
  2. Providing concrete data to <\/span>inform government policy<\/b> and funding decisions.<\/span><\/li>\n<\/ol>\n

    Training <\/span>AI models<\/b> to automatically detect accessibility issues, helping to scale the auditing process<\/span> even further<\/span>.<\/span><\/p>\n

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    Figure 2.<\/strong> (top) A screenshot of a user virtually auditing sidewalks in Mexico showing labels for a curb ramp (green), missing curb ramp (red) and crosswalks (yellow). (bottom) A user validating an obstacle-in-path label in Amsterdam.<\/em><\/p>\n

    Making a Difference, Street by Street, City by City<\/span><\/h2>\n
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    Figure 3.<\/strong> The PacTrans-supported Project Sidewalk is now deployed in 35 cities across 8 countries including the US, Canada, Mexico, Ecuador, Netherlands, Switzerland, and New Zealand. Project Sidewalk users have analyzed over 21,380 km of city streets contributing over 1.1 million labels and 935k validations.<\/em><\/p><\/div>\n

    Working with NGOs, disability advocates, community groups, and local governments, Project Sidewalk is now deployed in 35 cities across 8 countries including the US, Canada, Mexico, Ecuador, The Netherlands, Switzerland, and New Zealand (Figure 3). Incredibly, Project Sidewalk volunteers have contributed over 1.1 million sidewalk accessibility labels, covering more than 21,350 km of city streets (over 13,200 miles). To our knowledge, this is the largest open sidewalk accessibility dataset ever collected.<\/span><\/p>\n

    And it\u2019s leading to tangible change:<\/span><\/p>\n