Open traffic lights: a strategy for publishing and preserving traffic lights data

For better traffic flow and making better policy decisions, the city of Antwerp is connecting traffic lights to the Internet. The live "time to green" only tells a part of the story: also the historical values need to be preserved and need to be made accessible to everyone. We propose (i) an ontology for describing the topology of an intersection and the signal timing of traffic lights, (ii) a specification to publish these historical and live data with Linked Data Fragments and (iii) a method to preserve the published data in the long-term. We showcase the applicability of our specification with the opentrafficlights.org project where an end-user can see the live count-down as well as a line chart showing the historic "time to green" of a traffic light. We found that publishing traffic lights data as time sorted Linked Data Fragments allow synchronizing and reusing an archive to retrieve historical observations. Long-term preservation with tape storage becomes feasible when archives shift from byte preservation to knowledge preservation by combining Linked Data Fragments. This is a print-version of a paper first written for the Web. The Web-version is available at https://brechtvdv.github.io/Article-Open-Traffic-Lights