Here is a very nice video showing car flow in San Diego highway organized by color preference of contemporary San Diego drivers.
This source footage for this video is a 4-minute shot from the Washington Street bridge above State Route 163 in San Diego captured at 2:39pm Oct 1, 2013. The methodology can be found at here. This kind of research can be used for data-driven survey of car usage, traffic pattern, people preference, etc.
One possible extension is that we could public traffic camera network to study the traffic pattern and car types in urban system, such as the Real Time Traffic Cameras in New York city. In their traffic camera network, every cameras are refreshed one time per second.
Urban Computation 