In an effort to ease congestion, the Massachusetts Bay Transit Authority is introducing a pilot program that will leave few to no seats in the middle two cars of a six-car Red Line train.

Beginning today, these high-capacity “Big Red” cars will hold an additional 28 passengers per car, increasing capacity by about 10 percent, MBTA spokesperson Lydia M. Rivera said.

She said that the MBTA has equipped the new cars with additional straps and hand rails for customers to hold onto while riding.

Only one train with Big Red cars will be in service for the weekday rush hour period. The cars will be labeled with signs, so customers will be able to choose whether or not to take the new trains with fewer seats.

The trial period for the pilot program will run indefinitely while the MBTA garners and gauges customer feedback.

“We’re just hoping the customer will enjoy the experience. Some people will find it accommodating,” Rivera said.

The MBTA plans to allow customers to provide feedback online and via surveys that will be available on cards in the new trains.

Congestion has steadily increased on the T as ridership has risen 5.5 percent this year, according to information released by the MBTA last week.

Red Line patron Richard F. Days said he has experienced the crowding first hand.

“I felt like a sardine,” he said of an experience last summer on the T.

Mary C. Roche, another T rider, said she has experienced packed T cars as well but still expressed her misgivings about the MBTA’s new program.

“On one ride people actually had to get off. I think that’s dangerous and unhealthy. But I myself don’t think these Big Red cars are going to solve anything. They should just add another car to the trains instead.”

Despite criticism for the program, Rivera stressed the MBTA’s commitment to customers.

“Basically we just want to emphasize that customer feedback is very important in this, and we do listen to our customers. We’re experiencing an influx in ridership that continues to grow,” Rivera said. “We are working diligently to accommodate that ridership while at the same time keeping costs low.”