Commuters would encounter some subway cars with fewer seats, additional handrails and more overhead handles to grab as Metro begins a test of ways to squeeze more people onto a rail system already at capacity.

The plan -- which received preliminary approval yesterday and will begin in the spring if the full board approves it this month, as expected -- calls for installing cameras on two dozen test cars to study how three seating arrangements with up to 32 fewer seats and 40 percent more handrails could accommodate more riders and allow them to move on and off trains more quickly.

The decision to try out various interior designs is part of Metro's effort to find inexpensive ways to increase capacity and efficiency on trains and platforms as daily ridership surpasses 700,000.

"The seating configuration was laid out when Lyndon Johnson was president, and we were hoping people might leave their Oldsmobile at home and try transit. Now we're dealing with success," said board Chairman T. Dana Kauffman, who represents Fairfax County.

Seats on the 24 test cars will be laid out in one of three ways.

Eight of the test cars will have 48 seats, instead of 64 to 80 in current cars. They also will have four folding seats at the front, as well as padded, waist-high rests for standing riders and more open space for wheelchairs and bicycles.

Another group of eight cars will have 52 seats with additional seating against the wall near the center door. And a third group will have 64.

All of the cars will have double handrails anchored to the ceiling above the aisle, some with spring-loaded metal handles for shorter passengers. Vertical poles near doorways will be replaced by handrails that extend from the seat backs to the ceiling.

The test designs also have fewer windscreens -- the partitions near doorways that riders tend to lean on, blocking the door.

Testing the designs will cost about $783,000, officials said.

Once Metro officials decide on a new seating design, it could take several years to reconfigure the agency's 952 cars.

At yesterday's meeting of a committee that oversees planning for the subway system, officials got a chance to see for themselves how passengers board, exit and move around today's train cars. Video taken aboard 16 cars beginning in August showed consistent problems:

Riders clustered near the doors, whether the trains were packed or virtually empty, and the floor-to-ceiling pole in front of the double doors was an obstruction that people gravitated to or had to make their way around.

"We didn't do a very good job of enticing people down the aisles," said Jeffery Pringle, senior program manager, who presented the study to board members.

If passengers did venture away from the doors, the video showed, they had to dodge other riders who were stationed in the middle of the aisles holding onto the rail bolted into the ceiling directly above them.

To come up with the three seating design proposals, Metro staffers combined information from the videos with suggestions from elderly and disabled riders, as well as a panel of about 12 riders.

Leona Agourdis, assistant general manager for customer relations, said this was the first time Metro has consulted riders to this degree for large-scale changes. The move represents a broader effort to be more responsive to Metro's customers, she said.

"In the past, the system has made changes from one fleet to the next without really having that kind of discussion. We didn't do a lot of analysis. We didn't talk to customers about it. We didn't try anything out," said Chris Zimmerman, who represents Arlington County on the Metro board.

The study of current cars, which cost more than $200,000, confirmed what some Metro engineers had suspected and have incorporated into the design of 184 cars that will be added to the fleet this spring, Pringle said.

Although board members said yesterday that they favor the 24-car test, and approved it unanimously, some members voiced concerns. Robert J. Smith, Montgomery County's representative, asked whether folding chairs will be safe.

As the representative for suburban riders in Fairfax County, Kauffman said he is concerned about having fewer seats available for people with long commutes.

Board member Dan Tangherlini, director of transportation in the District, suggested that Metro keep gathering ideas. He offered, for example, the possibility of moving away from the two-by-two "love seat arrangement" and fitting in more seats by installing benches along the outer walls of cars, similar to seating on the New York subway and London Underground.

"We're building a new car here, and maybe we need to be thinking of a new paradigm," he said.

Passengers squeeze onto a crowded Orange Line. "The seating configuration was laid out when Lyndon Johnson was president. . . . Now we're dealing with success," said board Chairman T. Dana Kauffman, who represents Fairfax.