Yesterday New York City opened up 200 high value data sets to the public, making it possible to use this data to improve OpenStreetMap. In return, New York City’s GIS team can now be informed of changes made in OpenStreetMap around their datasets - helping them to keep their map data current. This move effectively makes the largest municipality in the United States an OpenStreetMap participant. This is an exciting example of connecting governments to open data communities, step by step moving towards a future where citizens and government collaborate directly around the same datasets.

New York City building perimeter outlines (practically complete) compared to OpenStreetMap (sparse)

With yesterday’s release, New York City’s government continues to follow through on last year’s law on the opening of government data, effectively releasing troves of city data into the public domain. The release encompasses a large variety of data sets, but there are two particularly interesting ones for the OpenStreetMap project: an update to building perimeter outlines and a brand new release of address points. Both are of amazingly high quality.

Over the last few weeks we’ve worked with the New York City Department of Information Technology and Telecommunications (DoITT) and the OpenStreetMap community to start an import of this data into OpenStreetMap and furnish New York City with a change feed of buildings and addresses in New York City.

Change detection

Every day, starting last month, New York City’s GIS department receives a notification of changes to buildings and addresses in OpenStreetMap. A New York City employee can review these changes and use them to verify the change and update the corresponding New York City dataset accordingly. By the way, this is just connecting dots between open data sets - no private information is being shared. The change detection code is open source and available through GitHub.

Daily change detection email, notifying New York City’s GIS department of building and address changes in the city

Building and address import

The above change detection will get really interesting for New York City once buildings and addresses in OpenStreetMap are of comparable quality to city data. To this end we are working closely with the OpenStreetMap community to start an import of high value building perimeter outlines and address points. At this point, the import is in the peer review phase. Take a look at the proposal on the OpenStreetMap Wiki to get involved.

Interactive map of New York City’s building perimeter data set containing over one million buildings in all five boroughs.