Bloomberg was shown around a closed-circuit television facility at Westminster Underground station by London Mayor Boris Johnson on Tuesday.
There are 12,000 cameras on London's subway system, and city officials tout their role in combating crime and terrorism.
New York City has far fewer such cameras - about 4,000 along its subways - and Bloomberg has complained that half of them don't work. Police, instead, have had to rely on regular patrols and random bag searches.
"Crime rates in both the subway systems in London and New York City are as low as you can get, but there's always the threat of terrorism. ... Wouldn't you want to be safe?" Bloomberg told reporters. "I am here to learn from others, see what works best, and try to fix things before they become a problem."
London has one of the world's highest concentrations of surveillance cameras, with an expanding ring of them encircling the central business district. The so-called "ring of steel" was the inspiration for a 3,000-camera network being installed in lower Manhattan and midtown New York.
The New York Police Department hopes to install the 3,000 cameras by the end of 2011. It is also using private surveillance installed in major buildings as part of a massive security initiative.
Bloomberg is making this field trip less than two weeks after the failed car bomb attempt. The street camera with the best view of that scene turned out to be dead.
That was the issue when police brass meet Tuesday with hundreds of business leaders at One Police Plaza. There have been security conferences like this before, but this is the first since the Times Square incident.
Police will stress the need for private companies to maintain and expand their own security systems so they can be part of the grid in Lower Manhattan, as well as the new system envisioned for Midtown, between 34th and 59th streets.
Security experts say the London cameras and sensors have helped investigators there. The machines, though, were no help in preventing the suicide bombings in the London subway system.
"It's intuitive that more cameras mean we are safer," said Mike German, of the American Civil Liberties Union. "Well, reports and evidence and studies show that that's not the case."
Be that as it may, polls show that Americans favor increased surveillance.
