In a few weeks, Viacom Outdoor plans to install in the London Underground video posters with changing text and animated images. The Digital Escalator Panels are made of liquid crystals that realign under electrical stimulation.

“It’s not television, but it’s not a poster. If anything, it’s poster plus,” explains Nicky Cheshire, from Viacom Outdoor.

Companies can refresh messages daily and even hourly. A newspaper advertiser could update ads to promote breaking news, for example and prices will rise and fall according to traffic patterns.

In Germany, digital advertising is already ubiquitous in Berlin’s train stations where digital signs display a mix of advertising and subway information.

Yet to be decided is how to keep the messages from posing a safety issue by distracting passengers, since they can combine light, color, moving images, text and sound.

Copenhagen and Berlin have chosen to silence advertisements.

Barcelona let music and sound roll with trains. London has decided to mute its trial-run ads and will shun television and film advertising, to avoid slowing pedestrian traffic.

Via International Herald Tribune.