A Metro board safety committee recommended yesterday that Metro reverse years-old policy and tell subway riders how to open car doors and escape in an emergency.

The proposal, which the full Metro board is expected to approve today, calls for posting instructions and installing equipment that would allow passengers to open the doors of a stopped train. However, passengers would not be able to stop a moving train.

Metrorail's cars now contain no escape instructions, on the grounds that such knowledge might be a hazard if pranksters abused it or if panicky riders jumped onto the 750-volt third rail. Evacuations should take place only under the guidance of the train's operator or rescue teams, Metro has argued.

That approach has been under attack from the National Transportation Safety Board and area fire department officials, who have long called for escape instructions to be available for passengers.

The board's three-member safety committee, set up after the Jan. 13 derailment that killed three people, includes representatives from Maryland, D.C. and Virginia. "I am confident that the full board will support us on this," said committee Chairman Carlton Sickles of Maryland.

If the policy is adopted, "you won't have the possibility of a situation where the passengers are trapped in a car," Sickles said. "We're going to have to have an education program with the community to impress upon them not to jump out every time a car stops in the tunnel."

In testimony to the committee before the vote, fire officials from Washington and Arlington and Montgomery counties said that supervised evacuation of passengers would be preferable, but in a severe accident, rescue teams might arrive too late to save people from flames and smoke.

Passengers cannot be expected to wait for rescue calmly in a burning train, D.C. acting assistant fire chief H. H. Shaffer told the committee. "If that train is on fire, those passengers are coming off that train" by whatever means they can find, he said, and Metro should facilitate their escape.

Battalion Chief Robert S. Carpenter of the Arlington County Fire Department said that in studying incidents in which riders left other subways' trains while third-rail power was on, he had found no case of anyone's being killed by the rail.

"I don't think that third rail is quite as big a bugaboo as we think," he said.

The fire officials all indicated that passengers should not be able to stop trains. Stations are the best place to evacuate trains, they agreed, and trains in trouble should not stop in a tunnel.

The testimony yesterday came one month after officials from Montreal, Toronto and San Francisco told the committee that evacuation information for passengers is considered key to safety in those cities' subways.

According to the American Public Transit Association, only two U.S. transit systems, Metro and the Port Authority Transit Corporation of Philadelphia, do not give passengers escape instructions.

Under the committee's proposal, door-opening mechanisms in Metro's 300 cars would be modified to facilitate opening, and instructions would be posted on how to do it. Three hundred new cars now on order would be changed, too.

Opening mechanisms of cars now in service are located behind advertising panels on either side of the doors. To open a door, a panel must be unscrewed and a red lever behind it pulled. If this is done while the car is moving, the door will open, but brakes will be automatically applied.

The committee proposed to modify this equipment so that the mechanism would not work or passengers could not get to it while a train was still moving.