Scientific American: What is congestion charging?
Congestion charging or pricing is the practice of setting up cordon tolls around the city on a large-scale to charge entrants for entering during peak hours. Ideally, this is done in an automatic fashion with cameras registering your license plate and directly billing you. This is different from low emissions zones, which are specific zones that limit the type of vehicles that can enter, and when.
City-scale congestion charging is picking up steam as a policy tool...