GPS Free car tracking

Very clever!

An Automated GPS-Free Location System For Cars | IdeaFeed | Big Think:

It works through the use of two simple cameras, which collect video data that is then compared to an OpenStreetMap area map. Through a process of elimination that takes place within an average of 20 seconds of driving, the system is able to figure out exactly where the car is. During tests conducted in Germany, it located cars to within 3 meters of their actual positions.