This month local mappers, in collaboration with our data team at Mapbox, completed the task of adding missing buildings in the SF area. Our sprint focused on the whole of SF Peninsula covering the areas of Sunnyvale, Mountain View, Palo Alto and Menlo Park areas covering ~1290 sq.km. This is a continuation of our earlier efforts from 2014 when we addded ~114,000 buildings in San Francisco.

Based on the existing building density, we estimated a total of ~180,000 missing buildings in the project area, and finally traced ~173,447 buildings over the last two months.

Methodology and Observations

• An initial trial run was conducted to determine a rough estimate of the amount of buildings to be added. It was crucial to gather an idea to timebox the task to a particular timeframe.
• Regular reviews were conducted to determine any gaps in coverage and accordingly create new tasks.
• There were outdated imports in the area which needed to be cleaned up. Accordingly clean up tasks were created for these areas. Since these misaligned footprints aren’t due to any mapping efforts a separate ticket was created for the clean up tasks in mapping repository.
• Imagery is outdated in some cases, where new buildings have cropped up. One such instance was the new Apple spaceship campus in OpenStreetMap which was absent from Bing/Mapbox imagery.

Timelapse of building footprints added in the SF peninsula over the last 3 years

This task provided us with an opportunity to streamline our mapping efforts in the open and how we engage with the local community in the form of blog and diary posts. Feel free to join us in our current effort to clean up imported buildings in Palo Alto and Cupertino and also suggest other areas that require improvement.

Do drop into our mapping repository to track our latest OpenStreetMap mapping projects and provide your inputs in how we can be doing better. Happy Mapping!