Producing Linked Data for Smart Cities: The Case of Catania

Semantic Web technologies and in particular Linked Open Data provide a means for sharing knowledge about cities as physical, social, and technical systems, so enabling the development of smart city applications. This paper presents a prototype based on the case of Catania with the aim of sharing the lessons learnt, which can be reused as reference practices in other cases with similar requirements. The importance of achieving syntactic as well as semantic interoperability - as a result of transforming heterogeneous sources into Linked Data - is discussed: semantic interoperability is solved at data level in order to ease further development on top. We present a comprehensive data model for smart cities that integrates several data sources, including, geo-referenced data, public transportation, urban fault reporting, road maintenance and municipal waste collection. We show some novel ontology design patterns for modeling public transportation, urban fault reporting and road maintenance. Domain practitioners and general members of the public have been asked to play with the prototype, and fill out a survey with questions and feedbacks. A computational experiment has been also conducted to evaluate the performance of our data model in terms of practical scalability over increasing data and efficiency under complex queries. All produced data, models, prototype and questionnaire results are publicly accessible online.