How can Tokyo buses and streetcars make more money without attracting more passengers? One answer: advertising.

Expectations are now running high among train operators and ad agencies that the Tokyo Metropolitan Government will lift its ban on ads on train exteriors following a series of recent policy shifts.

Seen as a highly profitable advertising medium, train exteriors are the next target of ad agencies. A half-century-old metro ordinance on advertisements in public spaces, however, prohibits any kind of ad on the outside of trains that run in the capital.