Ads in subway tunnels

Residents of San Francisco, Boston, London and a few other cities might already be familiar with this phenomenon. The tunnel walls of the subway are one of the newest forms of advertising. Canada's SideTrack and New York's Submedia are some of the companies who are focusing on advertising on subway tunnel walls and some of the biggest brands like Microsoft, Target, Coca-Cola, Rebook and Honda are advertising on them.

SideTrack installed the system on San Francisco's Bay Area Rapid Transit (BART) system last month as a trial. How it works is that a long series of still photographs are installed in a subway tunnel which are illuminated by rapidly flashing spotlights as the trains go by, resulting in a movie like effect. Campaigns are 15 seconds long.

Michael Swistun, CEO of SideTrack, explained that his company's technology is designed to present riders with a 24- or 30-frame-per-second "movie," depending on the speed of the train.

The technology requires that trains pass the ads going at least 25 miles per hour. If they're going slower, the lights stay off and the tunnels stay dark.

Submedia has project pending in Paris, Prague, Singapore and India currently. Here is the Submedia India site.