The four new subway stations on the Orange Line in Arlinton, which will open Saturday along Wilson Boulevard, the country's historic main street, are expected to revitalize what is now a sleepy residential and business area.

Except for a high-rise condominium near the Virginia Square station and a few scattered medium-rise office buildings, most of this 2 1/2-mile stretch of Arlington is filled with one- and two-story shops and homes that date from the 1930s. The old, low buildings offer a stark contrast to glassy, high-rise Rosslyn, Arlington's first stop on the Orange Line.

Clarendon, as much of the area is known, was the Tyson's Corner of its day. Its decline began in the 1950s and its decaying stores and neighborhoods were characterized as a "disaster area" two years ago by a Chamber of Commerce official.

The subway stations are close together, less than a 15-minute walk apart. The proximity was planned to cope with the high-density development expected in the next 10 to 20 years.

The four new stations -- Court House, Clarendon, Virginia Square and Ballston -- will be the last of the county's subway stations until the East Falls Church station, also on the Orange Line, is completed in 1985.

No all-day or "kiss and ride" parking is provided by Metro at any of the stations, because they were designed as downtown Arlington stops, and Ballston was not originally planned to be even a temporary end-of-the-line station. This is expected to create some traffic and parking problems around the four new stations.

Arlington will celebrate the opening of the four stations with day-long festivities Saturday, with the official opening of the line at 1 p.m. at the Clarendon station. As part of the festivities, free rides will be offered from 8 a.m. to 4 p.m. Although the normal operating schedule will go into effect Sunday, no bus routes will be changed until Jan. 6, to allow time for what Metro officials call a "shakedown" of the additions to the subway system.