(PNN) - January 6, 2011 - Almost a decade after the events of September 11, 2001, significant downtown areas in some of the United States’ most prominent cities remain largely sealed off with metal gates and barriers. The explanation is that these urban areas allegedly need "security zones" to protect the populace from terrorist attacks. But a new study just published in the journal Environment and Planning A concludes this "architecture of fear" has done nothing but blight the landscape, limit public access and may promote paranoia.

"Our most open, public cities are becoming police states," study author Jeremy Nemeth, a University of Colorado Denver assistant professor of planning and design, said in a statement to the press. "While a certain amount of security is necessary after terror attacks, no amount of anti-terror architecture would have stopped the events of September 11, 2001, or the Madrid or London subway bombings; and by limiting access and closing off space, we limit the potential for more 'eyes on the street' to catch possible acts in the process."

If supposed continued terror threats dictate the need for so-called "security zones". Nemeth argues these areas should be planned and designed in ways that involve the public and are useful to downtown built environments. "Right now they consist of haphazard placement of metal gates, Jersey barriers and cones. But if these are to become permanent additions to the urban landscapes, we must understand how to integrate them into the existing built fabric," he stated.

The new study is the first to compare public and private security districts in multiple cities. It included research into areas of downtown Los Angeles, New York City and San Francisco and found that while each city values protecting potential terrorist targets, what each city considers off limits varies widely.

In fact, almost 40% of New York's civic center district is now in a "security zone" where it can be accessed only by people with the proper clearance. On the other hand, less than 4% of San Francisco's civic center area has the same designation. However, a huge 23 acres area of public space in Los Angeles has been placed in a hard-to-access "security zone".