Open data initiative, New York City, US  

Interaction type Government→Public→Government
Trigger event Adoption of open data policy.
Domain Local authority.
Organization NYC GIS Department and Department of Information Technology and Telecommunications (DoITT).
Actors NYC OpenStreetMap (OSM) community, NYC government, private sector.
Data sets Building footprint, addresses.
Process Data import into OSM and public maintenance in OSM platform.
Feedback Daily changes.
Goal Leverage volunteers to help keep authoritative data current.
Contact point Alex Barth, MapBox

 In September 2013, New York City released over 200 government data sets to the public as part of a broad open data initiative to “improve the accessibility, transparency, and accountability of City government.” Using the web-platform Socrata, the data is made available for download or through APIs (application programing interfaces) that allow software developers to construct mobile and web-based applications that incorporate this information. This data release continues an aggressive open data push by the city government that began in 2011. New York City’s open data law, signed by Mayor Bloomberg in March 2012, mandates that all city agencies “systematically categorize and make accessible in “open” formats all public data sets at no charge” before 2018. To date, over 1100 data sets have been made available on the city’s open data portal and numerous applications have been built that address issues ranging from transportation to food safety and the environment.

In partnership with the Department of Information Technology and Telecommunications (DoITT), the members of the local OSM community have begun to import city building footprint and address point data sets into the OSM database. These critical data sets, which are necessary to support a wide variety of data analysis and visualization projects, can be difficult and expensive to keep up to date in a city as large and dynamic as New York. Thanks to software developed by the company Mapbox, the New York City GIS department now receives daily emails detailing changes to OSM building or address information. These emails allow the GIS team to quickly assess updates in OSM to identify where new construction or other changes in the city may necessitate updates to the authoritative city data set.

Upon completion of the import of the city data into OSM, a feedback loop between the city and the volunteer OSM community allows both the government and the public to work together to create and make use of up-to-date and high-quality spatial data. Importing large and detailed data sets like addresses and buildings is a complex process that requires technical resources, significant labor and solid coordination between the OSM community and others involved. In this case the information released by DoITT was up to date and of high quality, but the same cannot be said of all municipal data sets. It should also be noted that DoITT has expressed interest in incorporating OSM into other parts of their data management practices but have so far been unable to due to the conflict between OSM’s share-alike license and the public domain license required by NYC open data mandates. There has also been a great deal of communication between the city government, the OSM community and the people working on the import, which is critical to the success of these kinds of efforts. It will be important and useful to revisit this project in the future in order to learn more but so far it provides an excellent example of cooperation between local government and the volunteer OSM community around open data.

Main lessons:

  • Releasing government data sets freely into the public domains means citizens can download and create their own applications.
  • VGI communities like those of OSM can keep government data sets up to date even in large, dynamic cities.
  • Cooperation between VGI communities and relevant government departments allows them to work together to create and make use of up-to-date and high-quality spatial data.
  • VGI communities and government departments can bring technical resources, significant labor and solid coordination.
  • Municipal data sets, even when of high quality, need to be maintained in order to stay accurate. This can be achieved effectively and at lower cost than via traditional practices through the cooperation of VGI communities and government departments.