Don’t wear rollerblades in the subway ($100 fine); get your feet off that seat ($50), and don’t even think about using the end doors to change cars ($75).

These are among the slew of new rules and fines that the board of the Metropolitan Transportation Authority approved yesterday in a unanimous vote. Keep in mind, too, that the $25 fine for drinking a cup of coffee on a subway car has not disappeared. How the rules will be enforced is unclear.

“If you’re walking around with a steaming hot coffee on the 5 train or the 4 train at 8:30 in the morning, I would hope to hell that cop would give you a summons because you have no right to do that,” the chairman of the MTA’s board, Peter Kalikow, said. “It’s just not smart, and it’s not courteous to your fellow passengers.”

In the face of widespread public criticism of the prohibitions, in particular those against moving between subway cars and drinking from open containers, the board decided against voting on the rules at its last meeting in July.

The opposition voiced by riders, politicians, and transit employees reflected a sense that the transit authority overstepped its mandate to ensure safe and reliable train service and had begun to infringe on personal liberty in the subway, which many consider to be as much a public space as a city sidewalk.

“If this is for the public, public opinion should matter,” one rider, Wendell Quintyne, 29, said. “And in this case, public opinion doesn’t matter to them.”

Riders did record a small victory yesterday: Transit officials clarified an existing rule and will now allow riders to take up more than one seat on empty subway cars.

The rules against open containers and changing cars also have drawn criticism for being confusing, but Mr. Kalikow abandoned efforts to add language he said would have clarified the prohibition against open containers.

“We’re not clarifying,” he said. “It’s not worth the argument.”

Still, beyond a cup of coffee, it is unclear which of the multitude of beverage containers, from sports water bottles to the 44-ounce Super Big Gulp, are illegal on subway cars.

Holding up a bottle of water with a screw cap, a nonvoting board member, Andrew Albert, asked whether it was illegal. The response from transit officials was hardly illuminating: It’s at the discretion of the police officer.

That, too, will be the standard for deciding whether a person moving between subway cars faces a $75 summons. Critics worry the police will enforce the rule haphazardly.

“The more discretion there is, the more potential there is for at least the appearance of unfair enforcement,” the associate director of the MTA’s Permanent Citizens Advisory Committee, William Henderson, said.

Repeating comments made by transit officials in July, Mr. Henderson said the ban was meant to give the MTA legal cover against lawsuits from people injured while moving between cars.

Mr. Kalikow did not address that issue yesterday. “We want the public to understand this is a safety item and it’s for everybody’s benefit,” he said, adding that the rule can be suspended during an emergency or when passengers are told to evacuate by a transit employee. What exactly constitutes an emergency remains a matter of police discretion.

A longtime critic of the MTA, Gene Russianoff, a senior attorney for the New York Public Interest Research Group’s Straphangers Campaign, said he supported the new rules as a matter of public safety and hoped they would be enforced using common sense. The Straphangers Campaign spent most of its energy on defeating a proposed ban on photography in the subway earlier this year.

Since 1996, there have been 13 fatalities and 117 injuries as a result of passengers moving between cars, a spokesman for the MTA, Paul Fleuranges, said. Subway riders said a lack of air-conditioning, an offending smell, or a menacing person were reason enough to move between cars.

Another rider, Johanna Contino, 27, said that since giving birth six weeks ago, she has taken to sitting at the ends of cars with her baby in a stroller. Although she welcomed not having to move for people passing between cars, she said the rule seemed draconian.

“No matter the reason, you should always have the option” to move between cars, she said.

For thousands of riders on some of the lettered lines, moving between cars is already impossible. The sliding doors on 1,600 of the system’s 6,400 cars have been locked since the 75-foot long cars were first introduced in 1971. Several years ago, however, the transit authority disabled an emergency latch meant to allow riders to unlock the doors after vandals abused the mechanisms, Mr. Fleuranges said. Riders on those lines have had long-standing concerns over how they might escape a car in a tense moment.

Mr. Kalikow yesterday directed the transit authority to install an intercom system that would allow passengers to communicate with a conductor, who could unlock the doors in an emergency.

Doors on the majority of cars, which are 60 feet long, will remain unlocked, Mr. Kalikow said.

The ban on moving between cars will not be actively enforced until the end of the year, by which time stickers on the doors will make riders aware that moving between cars is prohibited.

Despite public concerns over increased regulation, few fines for open containers have been issued in the last three years. Of the 336,700 tickets issued to riders for violating the rules of the subway in 2003 and 2004, 198,001 were for fare evasions, while 120 summonses were issued to people who violated the subway’s open container law, according to New York City Transit.