CBS Outdoor, which handles ad space in the stations, began selling entire stations to advertisers about 10 years ago, letting them wrap poles and put graphics on the floors.

More recently, it has offered stairs and the full interior of trains to advertisers for a technique known as a “wrap.”

And this year, it is getting even more creative.

“Advertisers, especially in this environment, are looking to do something different and be noticed,” said Jodi Senese, the executive vice president for marketing for CBS Outdoor. “When something is new, clearly there’s an opportunity to make a big splash,” she said.

This week, the company began testing advertising on a large display, almost the size of a movie screen, mounted above a passageway by the 7 train in Times Square.

Because the New York subway runs 24 hours a day, it is difficult to put ads on the far side of subway tracks. Consequently, CBS is considering projecting images across the track. They will be similar to ads that are projected onto station walls, which CBS began about two years ago. There is a projection ad for Asics in Union Square, in the passageway between the N, Q, R and W lines and the Lexington Avenue line, and one for the Navy at Grand Central, in the corridor to the shuttle.

Both the arms of turnstiles and the entire turnstile structures are available to advertisers.

And starting in 2009, CBS will sell advertisers exterior panels — thinner versions of the horizontal advertisements that buses carry — on the 1, 2, 3, 4, 5, 6, 7 and shuttle trains. These panels are already in place on some 1, 3, 4, 7 and shuttle trains, where the History Channel is the first advertiser to use them. It is promoting its “Cities of the Underworld” series.