In what country was the first parking meter installed?

A parking meter is a device used to collect money in exchange for the right to park a vehicle in a particular place for a limited amount of time. Parking meters can be used by municipalities as a tool for enforcing their integrated on-street parking policy, usually related to their traffic and mobility management policies, but are also used for revenue.

An early patent for a parking meter, US patent, was filed by Roger W. Babson, on August 30, 1928. The meter was intended to operate on power from the battery of the parking vehicle and required a connection from the vehicle to the meter.

Holger George Thuesen and Gerald A. Hale designed the first working parking meter, the Black Maria, in 1935. The History Channel's... History's Lost and Found documents their success in developing the first working parking meter. Thuesen and Hale were engineering professors at Oklahoma State and began working on the parking meter in 1933 at the request of Carl C. Magee of Oklahoma City, Oklahoma, United States. The world's first installed parking meter was in Oklahoma City on July 16, 1935.