Ron Marsico, a spokesman for the Port Authority, said the agency’s fleet of PATH trains could absorb the 4 percent increase in ridership. Mr. Marsico added that the agency recently replaced its fleet of 340 cars, with new ones that allow customers to enter and exit more quickly.

Over the next few years, he said, the Port Authority will also replace its mechanical switches with computers that will allow trains to run closer together.

Joshua Crandall, who runs CleverCommute.com, a Web site where commuters share up-to-the-minute information on bus and train delays with other members, said even some affluent customers had been persuaded to leave their cars at home.

“The decision has become easier to say ‘I’m going to get on the train,’ ” he said.

The Port Authority experienced a similar drop in car traffic after raising tolls to $8 from $6 in 2008, Mr. Marsico said. But that decline was temporary. PATH ridership also rose after the toll increase, but fell in 2009, largely because of the economy, before rebounding somewhat in 2010.

Before the September toll increase, Erica Yahr had driven into Manhattan from Montclair, N.J., one to two days a week for the past 15 years. She is no cheapskate: She recently splurged on an iPad, often has lunch at Pret a Manger and has dinner out. But now she takes the train every day.

“I will not drive in on my own dime anymore,” Ms. Yahr said. “It just has to do with how big of a hike at one time that they did. It’s just obnoxious.”

Longtime bus and train riders have also noticed the change. Michael Catchpole, who has been taking the Decamp 33 Grove bus into Manhattan for the past three years, said that before the toll increases, he could find a seat four days a week, but he is now lucky to sit once a week.

Two to three days a week, he said, buses are so crowded that they do not stop at all.

“Suddenly there was barely even room to stand on the bus,” he said.