Cambridge Adopts PDDL License for Open Data: A Milestone for Enhanced Usability and Public Trust

The City of Cambridge today announced the adoption of the Public Domain Dedication and License (PDDL) for its open datasets. This license ensures that users can freely access, modify, and share the City’s robust datasets without legal encumbrances, while clearly communicating that that the city provides its data without warranty.

“This decision marks a pivotal moment in our ongoing commitment to transparency, innovation, and public engagement,” said Cambridge City Manager Yi-An Huang. “Historically, the lack of explicit intellectual property (IP) licenses for our open datasets may have led to uncertainty and hesitation among potential users. This ambiguity not only limited the data's potential impact, but also hindered our civic engagement goals. We are excited about the possibilities this opens up for our community and beyond.”

Cambridge Open Data is free public data published by a wide range of City of Cambridge departments. The PDDL, known for its simplicity and clarity, explicitly dedicates data to the public domain, removing barriers to its use and reuse. This approach aligns with Cambridge’s vision of fostering an environment where data serves as a tool for innovation, research, and community development.

"Adopting the PPDL clearly articulates Cambridge's commitment to the principles of openness and accessibility that were established with the Open Data Ordinance of 2015," stated Reinhard Engels, Data Analysis & Open Data Program Manager. "Since then, we have released over 300 open datasets and other data assets. Now the public has greater clarity on how they can best leverage these valuable resources."

The Open Data Review Board (ODRB), consisting of a mix of public members and representatives from City Departments, has long identified the adoption of an open license as an important priority for the Open Data Program. The decision to adopt the PDDL was inspired and informed by precedents in other cities, including Boston and San Francisco, who have successfully implemented public domain licensing for their open data. Their overwhelmingly positive experience helped Cambridge appreciate the value of a standard license that is commonly understood and has been tested in court.

Implementing the PDDL will not disrupt access to the City’s data. The PDDL will be applied on a per-dataset basis, ensuring that only appropriate resources are released under this license. Datasets released under the PDDL with be clearly marked as such, signifying to users that they can confidently use the data with the knowledge of its free and open status. City of Cambridge sites containing data that will be released under the PDDL include the Open Data Portal, the GIS Data Repository, the GIS Data GitHub repository and ArcGIS Online.

When Cambridge's City Council passed the Open Data Ordinance in September of 2015, it instructed the City to view data as a tool for achieving greater transparency, efficiency, and innovation, while instructing staff to seek balance between making data available and protecting privacy. Though the program has grown in scope and scale since then, these same values remain its guiding principles. The City anticipates that this transition to the PDDL will not only clarify the legal status of its data, but also encourage its broader use, driving innovation and fostering a more informed community.