If you are looking for data on a particular subject. It is often helpful to think about who may be interested in a particular type of data. For example, if you wanted to start either a road construction or public transportation company in Nashville and wanted some traffic data to justify your business goals, the Tennessee Department of transportation (TDOT) collects traffic data out of their own interests and shares this with the public. Not every organizations chooses to share their data (government entities are legally required to, but private entities are not), but this is always a good start if you are having issues finding information about your specific topic!