Congestion pricing or congestion charges is a system of surcharging users of public goods that are subject to congestion through excess demand, such as through higher peak charges for use of bus services, electricity, metros, railways, telephones, and road pricing to reduce traffic congestion; airlines and shipping companies may be charged higher fees for slots at airports and through canals at busy times. Advocates claim this pricing strategy regulates demand, making it possible to manage congestion without increasing supply.
Electronic Road Pricing gantry in Singapore, the first place in the world to implement an urban cordon area congestion pricing scheme.
At Old Street, street markings and a sign (inset) with the white-on-red C alert drivers to the congestion charge, London.
Rome's Traffic Limited Zone (ZTL) entry control point with automatic surveillance.
Trängselskatt automatic control point at Ropsten, Stockholm. The sign on the right informs the drivers about the different fees, which vary depending on the time of the day.
In economics, a public good is a good that is both non-excludable and non-rivalrous. Use by one person neither prevents access by other people, nor does it reduce availability to others. Therefore, the good can be used simultaneously by more than one person. This is in contrast to a common good, such as wild fish stocks in the ocean, which is non-excludable but rivalrous to a certain degree. If too many fish were harvested, the stocks would deplete, limiting the access of fish for others. A public good must be valuable to more than one user, otherwise, its simultaneous availability to more than one person would be economically irrelevant.
Lighthouses are often used as an example of a public good, as they benefit all maritime users, but no one can be excluded from using them as a navigational aid.
Yosemite National Park, an example of an environmental good.
