The Lower Manhattan Security Initiative, as the plan is called, will resemble London's so-called ring of steel, an extensive web of cameras and roadblocks designed to detect, track and deter terrorists. British officials said images captured by the cameras helped track suspects after the London subway bombings in 2005 and the car bomb plots last month.
If the program is fully financed, it will include not onlybut also 3,000 public and private below Canal Street, as well as a center staffed by the police and private security officers, and movable roadblocks.
"This area is very critical to the economic lifeblood of this nation," New York's police commissioner, Raymond W. Kelly, said in an interview last week. "We want to make it less vulnerable."
But critics question the plan's efficacy and cost, as well as the implications of having suchover such a broad swath of the city.
For a while, it appeared that New York could not even afford such a system. Last summer, Kelly said the program was in peril after the city's share of Homeland Security urban grant money was cut by nearly 40 percent.
But Kelly said last week that the department had since obtained $25 million toward the estimated $90 million cost of the plan. While $15 million came from Homeland Security grants, he said, another $10 million came from the city, more than enough to install 116 license plate readers in fixed and mobile locations, including cars and helicopters, in the coming months.
The readers have been ordered, and Kelly said he hoped the rest of the money would come from additional federal grants.
The license plate readers would check the plates' numbers and send out alerts if suspect vehicles were detected. The city is already seeking state approval to charge drivers a fee to enter Manhattan below 86th Street, which would require the use of license plate readers. If the plan is approved, the police will most likely collect information from those readers too, Kelly said.
But the downtown security plan involves much more than keeping track of license plates. By the end of 2008, 3,000 surveillance cameras would be installed below Canal Street, about two-thirds of them owned by downtown companies. Some of those are already in place. Pivoting gates would be installed at critical intersections; they would swing out to block traffic or a suspect car at the push of a button.
Unlike the 250 or so cameras the police have already placed in high-crime areas throughout the city, which capture moving images that have to be downloaded, the security initiative cameras would transmit live information instantly.
The operation will cost an estimated $8 million to run the first year, Kelly said. Its headquarters will be in Lower Manhattan, he said, though the police were still negotiating where, exactly, it will be. The police and corporate-security agents will work together in the center, said Paul J. Browne, the chief spokesman for the police. The plan does not need City Council approval, he said.
The Police Department is still considering whether to use, an inexact science that matches images against those in an electronic database, or biohazard detectors in its Lower Manhattan network, Browne said.
The entire operation is forecast to be in place and running by 2010, in time for the projected completion of several new buildings in the financial district, including the new Goldman Sachs world headquarters.
Civil-liberties advocates said they were worried about misuse of technology that tracks the movement of thousands of cars and people,
Would this mean that every Wall Street broker, every tourist munching a hot dog near the United States Court House and every sightseer at Ground Zero would constantly be under surveillance?
"This program marks a whole new level of police monitoring of New Yorkers and is being done without any public input, outside oversight, or privacy protections for the hundreds of thousands of people who will end up in NYPD computers," Christopher Dunn, a lawyer with the New York Civil Liberties Union, wrote in an e-mail message.
He said he worried about what would happen to the images, once they were archived, how they would be used by the police and who else would have access to them.
Already, according to a report last year by the civil-liberties group, there are nearly 4,200 public and private surveillance cameras below 14th Street, a fivefold increase since 1998, with virtually no oversight over what becomes of the recordings.
Browne said the Police Department would have control over how the material is used. He said the cameras would be recording in "areas where there's no expectation of privacy" and that law-abiding citizens had nothing to fear.
"It would be used to intercept a threat coming our way, but not to collect data indiscriminately on individuals," he said.
Browne said software tracking the cameras' images would be designed to pick up suspicious behavior. If, for example, a bag is left unattended for a certain length of time, or a suspicious car is detected repeatedly circling the same block, the system will send out an alert, he said.
Still, there are questions about whether such indeed serve their purpose.
There is little evidence to suggest that deter crime or terrorists, said James J. Carafano, a senior fellow for homeland security at the Heritage Foundation, a conservative research group in Washington.
For all its comprehensiveness, London's ring of steel, which was built in the early 1990s to deter Irish Republican Army attacks, did not prevent the July 7, 2005, subway bombings or the attempted car bombings in London last month. But the British authorities said the cameras did prove useful in retracing the paths of the suspects' cars last month, leading to several arrests.
While having 3,000 cameras whirring at the same time means loads of information will be captured, it also means there will be a lot of useless data to sift through.
"The more hay you have, the harder it is to find the needle," Carafano said.