By Ron Nixon

New York Times News Service

BOSTON — At a mock airport in an underground laboratory here at Northeastern University, students pretending to be passengers head through a security exit in the right direction, while a young man enters going the wrong way. On a nearby computer screen, a newly developed video surveillance software program flags the wayward person and sounds an alarm.

In a lab across the street, researchers are developing a new way to detect explosives using radar. Just down the hall, a professor and a team of students are working on a scanning system that they hope will speed up security lines. The system uses machines installed in walls or other places to scan passengers as they walk past instead of having them walk individually into a scanning machine.

“The goal is to have a system that provides better scanning of individuals going through security, while at the same time making it more convenient,” said Jose Martinez Lorenzo, a professor of mechanical and industrial engineering, who is directing the project.

But the ambitious research in the name of passenger safety and easing air travel delays is colliding with pressure to protect privacy and to reduce federal spending.

“As we adopt new technologies to meet the constantly changing needs of our aviation infrastructure in a budget-constrained environment, these technologies must be proven to be effective, protect civil liberties, and properly balance security with passenger privacy,” said Rep. Bennie Thompson, D-Miss., the ranking member on the Committee on Homeland Security.

The video surveillance software was developed by Octavia Camps and Mario Sznaier, both engineering professors, to detect passengers going the wrong way through exits, and it has been tested since April 2014 at Cleveland Hopkins International Airport. The software is used at one exit, which handles 50,000 people a week, and has a 99 percent detection rate with only five false alarms a week, according to local officials.

The Northeastern researchers are developing additional uses for the video surveillance systems, including detection of suspicious packages left unattended and software that would recognize “coordinated activities” among individuals.

Airport officials say passengers entering restricted areas through exits pose a major security threat and can cost airports and airlines millions of dollars.

Last year in Detroit, for example, flights were canceled and a terminal was shut until a passenger who had gone the wrong way through an exit lane had been located. Irate passengers bombarded social media and airport phone lines.

“While it’s not a common occurrence, when it happens it can cause severe disruptions to air travel,” said William Young, a former Transportation Security Administration official who worked in Cleveland during the testing. “It’s a major security challenge for the TSA.” Young approached researchers at Northeastern about developing the software.

Another part of the advanced video analytics technology developed by Camps and Sznaier, which is known as the Video Analytic Surveillance Transition Project, or VAST, will solve the problem of false alarms by not only detecting a person trying to enter the secure area through an exit, but also by remembering that person’s identity using details such as their size and shape as well as the texture and color of their clothing. This allows security personnel to track them throughout the airport without having to shut down a terminal or the entire airport.

But not everyone embraces the new method of surveillance. Kade Crockford, director of the Technology for Liberty project of the American Civil Liberties Union of Massachusetts, said numerous questions remain about the potential widespread use of video analytics tools.

“There are so many issues raised by the use of these technologies,” she said. “Will the cameras have face-recognition capabilities, able to track your every move and tap into your Social Security number and other personal information?”