The highest ratings in a 179-page assessment released Wednesday went to the regions centered on Washington, D.C.; San Diego; Minneapolis-St. Paul; Columbus, Ohio; Sioux Falls, S.D.; and Laramie County, Wyo. The lowest scores went to regions centered around Chicago; Cleveland; Baton Rouge, La.; Mandan, N.D.; Yellowstone County, Mont.; and American Samoa.

All 75 areas have policies in place for interoperability, the report said, noting that "cooperation among first responders in the field is strong." However, "formalized governance (leadership and planning) across regions has lagged."

Of the areas checked, more than 60 percent are able to talk to each other in a crisis. But only 21 percent showed the "seamless use of equipment" needed to communicate with each other and with state and federal officials, the report said.

The assessment looked at many factors for why firefighters, police and medical personnel in cities, counties and towns fail to provide top-notch interoperability, including their reliance on older technology. But DHS Secretary Michael Chertoff said outdated technology is not the only impediment to progress.

"Interoperability...is more than just a matter of technology," he said in remarks posted on the DHS Web site. "People tend to think about it as 'We've just got to find the right radio or the right communications device and then everybody can talk to everybody else.' But in fact, true interoperability also involves matters of governance, policy making...[and] standard operating procedures."