A congestion charge is a fee that is imposed on vehicles for entering a designated area of a city during peak traffic times. The goal of a congestion charge is to reduce traffic congestion and improve air quality by encouraging people to use public transportation or alternative modes of transportation, such as biking or walking, instead of driving. Congestion charges are often implemented in urban areas where traffic congestion is a significant problem. They are usually enforced through the use of tollbooths, electronic sensors, or cameras that capture the license plates of vehicles entering the designated area. The amount of the charge is typically based on the type of vehicle, the time of day, and the length of time the vehicle is in the designated area.