Significant gaps in security at the nation's airports could be curtailed even at a time of rising passenger traffic by quickly making a wide range of relatively modest changes in screening people and bags, a confidential report by the Department of Homeland Security has concluded.
Fixing serious weaknesses in the nation's aviation security system is critical as passenger traffic rises beyond levels seen before the attacks of Sept. 11, 2001, the report observed. This summer, passengers are expected to take about 200 million trips globally on the nation's airlines, up about 4 percent from last year.
The proposed fine-tuning of airport security includes expanding the use of devices that can detect trace amounts of explosives and stationing more armed guards in secure areas.
''There is increasing pressure to increase the flow of passengers and their property through security checkpoints,'' the report said. ''Unfortunately, our analysis has shown there are significant security gaps at checkpoints as they currently exist.''
Widespread delays caused by security breaches could be reduced by simply preventing passengers from dashing through exits leading from secure areas, the report said. Checkpoints operated by the Transportation Security Administration, the division of Homeland Security that oversees airport security, should have gates or lockable doors at those exits, the report said.
And while the T.S.A. has an agreement with local law enforcement agencies to provide backup, if necessary, the arrangement is not enough, the investigators concluded, because it may take several minutes for an armed response.
''If, say, a handgun were discovered,'' the report says, ''the terrorist would have ample ability to retain control of it. T.S.A. screeners are neither expecting to encounter a real weapon nor are they trained to gain control of it.''
To speed the screening process, the report included some low-tech solutions, like setting up longer tables where passengers disgorge personal items into plastic bins. Because people are often backed up waiting to unload items, investigators found, the X-ray machines that examine carry-on baggage sit idle as much as 30 percent of the time.
Mark O. Hatfield Jr., a spokesman for the T.S.A., said steps were already being taken to speed passengers through airports without compromising security, including expanding checkpoints at airports in Atlanta, Denver and Washington. As a result, Mr. Hatfield said, even though passenger traffic is increasing, the average peak wait time at checkpoints has dropped a minute in the past year, to about 12 minutes.
''Getting as many people through as possible in a way that maintains or improves security -- that's the name of the game,'' he said.
The detailed security evaluation was necessary, the 214-page report says, because government officials made mistakes in rushing to improve aviation security after the Sept. 11 attacks.
''There can be no doubt that their efforts were Herculean, and the resulting system has made the nation safer,'' the report says. ''However, speed always comes at a cost, and the existing system may neither uniformly provide the degree of security desired, nor do it as efficiently and/or in as customer-friendly a fashion as might be achievable.''
The study, prepared at the request of Congress, looks at four areas: passenger checkpoints, checked baggage, air cargo and in-bound international flights. Staff members from the Department of Homeland Security and employees of Northrop Grumman, a giant military contractor, examined 5 domestic airports and 16 foreign ones, looking for quick ways to modify existing operations. The report, by the department's Science and Technology Directorate, was not intended to be released to the public, but a copy was obtained by The New York Times.
The point the report makes is not that the T.S.A. should stop its effort to deploy more advanced technology that can better detect bombs and other threats. It is just that in the interim, the existing technology can be used more effectively, largely to close the most serious gaps.