Metro's board set the dates yesterday for the opening of three new subway stations in the District and Prince George's County.

The Red Line's New York Avenue Station will open Nov. 20, and the Largo Town Center and Morgan Boulevard stations will open on a three-mile extension of the Blue Line on Dec. 18. Transit officials estimate that the stations will attract more than 10,000 new riders to the rail system each weekday.

And starting Sept. 27, Metrorail service will start 30 minutes earlier on weekdays, at 5 a.m. Metro officials said the change is projected to boost ridership by 1,700 customers a day and will give riders more breathing room during morning commutes.

The new stations represent milestones for the transit agency. The New York Avenue Station is the first to be built in the middle of a line. The Blue Line project marks the first extension beyond the original 103-mile system and is the first line in Prince George's County to reach past the Capital Beltway.

Riders on both lines will have to bear with a few disruptions while workers put the finishing touches on the new stations. Two Red Line closures will take place -- during the Columbus Day holiday weekend and in either late October or early November. Service between the Blue Line's Stadium-Armory and Addison Road-Seat Pleasant stations will likely be suspended the weekend of Oct. 22-24.

Officials tout the three stations as catalysts for economic growth and reduced traffic. Metro expects 1,500 new riders to use the New York Avenue Station and 9,300 new riders to use the new Blue Line stations each weekday.

"You would be hard-pressed to find a property owner near any one of these stations to say, 'I wish this station wasn't coming here,' " said Robert J. Smith, chairman of the Metro board. "It means incredible exposure."

The $103.7 million New York Avenue Station -- between Union Station and Rhode Island Avenue Station on one of Washington's busiest thoroughfares -- is the key to an eventual makeover of a downtrodden Northeast Washington area into a community of retail businesses, housing, office space and arts centers, officials said.

"It just provides a wonderful opportunity for the neighborhood to embrace Metro and use it to do their holiday traveling in addition to their normal work travel," said Gladys Mack, who represents the District on the Metro board.

One major complex already is being built near the New York Avenue Station. Plans for the station prompted the federal Bureau of Alcohol, Tobacco, Firearms and Explosives to construct a new headquarters on Florida Avenue NE, which will bring 1,100 employees to the area when it opens in the spring.

The two new stations on the Blue Line extension, which cost $456 million, will get some football fans off the roads and on the subway, officials said. Currently, spectators who take Metrorail to FedEx Field for Redskins games must take 20-minute shuttle rides from the Addison Road, Landover or Cheverly stations, a journey many spectators say deters them from taking Metro. The Largo and Morgan Boulevard stations are short walks from the stadium.

The Largo station will also deliver riders to the doorstep of Boulevard at the Capital Centre, a new shopping area in Prince George's, and, officials hope, inspire other development nearby. Both stations, which will provide connection points with county buses, will make life easier for locals, said Alfonso N. Cornish, a deputy chief administrative officer for the county.

"This is a huge one for our county -- it really provides our citizens and residents with a new transportation mode . . . for both work and for pleasure," Cornish said.

After Metro added five stations to the Green Line in 2001, ridership far exceeded estimates, causing major crowding. Mack said Metro is confident that the three new stations won't create a similar problem before 48 new rail cars arrive next year.

"We do have sufficient cars to service the new stations at this time," Mack said.

The New York Avenue Station on the Red Line is expected to open Nov. 20. It is the first station Metro has built in the middle of a line.