The London Underground advertising estate - successfully repitched for by CBS Outdoor in August last year - is the largest outdoor advertising contract in the world, with the 30,000 sites in stations and the 90,000 sites on Tube trains seen by 56 million people in 2006/2007 (source: Transport for London).
As part of its bid for the £1.6bn, 8.5-year contract, CBS Outdoor pledged to spend £72m upgrading the advertising network. Of this pot, 60% is to be spent upgrading the paper-based sites and 40% is being invested in three new digital products: digital escalator panels (DEPs), LCD units and cross-track projections (XTPs).
The Underground's paper sites have been brought into the 21st Century thanks to new, slimline frames designed with architects Arup, which are half the width of the existing designs, and, where illuminated (4,500 locations), twice as energy efficient.
In the frame
The plan is to frame every paper poster on the Tube and to increase the number of illuminated sites; where frames with glass are not viable (for example on curved walls), wet glue is being phased out thanks to a new system whereby posters peel on and off a clear film in the manner of "a giant Post-It note".
On the digital front, around five of the 18 planned DEPs have already been installed (at Euston, Charing Cross, Paddington, Baker Street and Tottenham Court Road) and more than 50 of the projected 225 LCD screens are in place.
The aim for the XTP digital sites is to introduce the format to around 20 of London's busiest stations, starting with Bond Street, replacing two or three of the average platform's 15 cross-track 48-sheet sites. The full digital roll-out will be completed by summer 2008.
According to Andrew Oldham, joint managing director, digital screens open up possibilities for creative work - the creatives for recent campaigns for Puma and Shelter linked across escalator panels.
London consumers are noticing the difference. In recent CBS Outdoor vox pops they reported that stations felt "warmer and safer". Oldham says: "Consumers are changing their behaviour on escalators - we are grabbing their attention."
Nicky Cheshire, director of the Alive digital division, adds that digital screens are more akin to broadcast media than posters, since they are in high-definition resolution, they are not static, and the message can be adapted according to the time of day.
Recent digital advertisers have included McDonald's, which booked daytime DEP sites to promote its deli range; Beck's, which advertised from 5pm only; and the Discovery Channel, which jumped at the chance to broadcast its new footage in HD.
Cheshire comments: "The standard of the ads has improved dramatically and continues to do so as the creative community starts to embrace digital Underground advertising and use it to its full potential."