tunnel advertising
n. An advertisement consisting of a series of illuminated screens in a subway tunnel, each projecting one image from a sequence to create an animation effect as the train goes by.
Submedia's tunnel advertising technology is based on a 19th century English toy — the zoetrope — which makes images inside a revolving cylinder appear to move, and passengers would view the illuminated ads as a train goes by.
—Anthony Tran, “US operator animated on moving picture subway ads,” The Standard, October 06, 2003
Tunnel advertising, which is being tested on the MARTA system in Atlanta, the New York-New Jersey PATH trains and subways in Athens and Seoul, would bring in about $400,000 annually and would take about eight months to introduce. The ads are a modern-day version of the famed Burma Shave signs of the 1930s to 1950s. BART riders would see the ads through the train window, watching a series of pictures mounted on the tunnel wall turn into a moving advertisement — sort of like a children's picture flip-book.
—Michael Cabanatuan, “BART seeking creative new ways to raise ad revenue,” The San Francisco Chronicle, February 28, 2003
2000 (earliest)
A recent push by the MTR which has seen a surge in the number of advertisements on trains, platforms and escalators is in danger of giving passengers ad-fatigue, experts have warned.

The Association of Accredited Advertising Agents of Hong Kong says the corporation — which is also considering between-station tunnel advertising — has already pushed the situation "to the extreme".
—Antoine So, “Tunnel vision on ads could backfire for MTR,” South China Morning Post (Hong Kong), May 28, 2000
Apparently there is no surface anywhere on earth that is safe from marketing messages. This latest form of advertising pestilence also goes by the names in-tunnel advertising and tunnel wall advertising.