Google has been helping people navigate urban areas and route around traffic for years now; as a result they’ve aggregated anonymized data about traffic patterns in hopes of solving cities problems around over-stressed public transit and traffic congestion. After funding a few pilot projects with cities such as Stockholm, San Francisco, and Chicago, preliminary results have been positive. In the Netherlands they’ve found that they could still accurately detect where and when traffic jams occur without the use of physical road sensors, potentially saving 50K Euro per year.

Source
Tackling Urban Mobility with Technology