1) Heterogeneous time-series data from various public sensors related to security, traffic, transportation, air quality and utilities could provide new insights if analyzed together, but the data is restricted by domain and lack of interoperability.
2) Connecting these data on a common platform would allow new analysis of relationships between factors like traffic and air quality, but overcoming heterogeneity in format, frequency, ownership and accessibility is challenging.
3) A case study combined traffic and air quality data to investigate the effect of traffic flow on local black carbon, requiring preprocessing to align the different data intervals and accounting for background levels and meteorological factors.