According to the city, all billboards within 200 feet of "arterial highways"—the West Side Highway, the FDR, the BQE, and major thoroughfares such as Brooklyn's Eastern Parkway—have been illegal since the 1940s. All ads put up on scaffolding and construction sheds are illegal, too, unless they're advertising the business whose signage has been covered up.
...once you know the rules, you realize that illegal ads are, literally, everywhere: on building walls, sidewalk sheds, phone kiosks, and alongside highways. There are so many of them, it makes you wonder if that city has given up on enforcing its own laws.
New York City's Struggle to Take Down Illegal Billboards
The city hasn't given up—over the past two years, New York has been fighting what amounts to a sign war with outdoor advertising companies. The Department of Buildings claims the ads are a threat to public safety and a major cause of visual pollution. The advertisers argue that the signs can't really be so bad if the city has neglected to take them down for decades.
In 2000, Mayor Rudy Giuliani announced that the city would be cracking down on the hundreds of illegal billboards lining the highways. The City Council raised the criminal fines for an illegal billboard from $5,000 to $25,000 and put size limits in place. Until then there had been no limit at all, and most advertisers had considered the fines to be "a small cost of doing business," according to city lawyer Gabriel Taussig. Billboards in high-traffic areas are estimated to draw more than $50,000 each month. Some can draw hundreds of thousands in revenue.
Eight years later, however, not a single billboard has been removed. After the zoning resolution went into effect in 2006, Clear Channel sued the city, saying that the laws infringed on its First Amendment rights. (According to SEC filings, the company had more than 16,000 advertising displays in New York that year.) Until the lawsuit is resolved, the buildings department can't take down any illegal billboards.