An erratic pattern of long and short gasoline lines continued at service stations in the Washington metropolitan area yesterday as lines virtually disappeared across the rest of the country.

Only the Washington and New York metropolitan areas and some cities in Louisiana were still experiencing hourlong lines at the end of last week, according to a Department of Energy survey. Over the weekend, however, the waits for gasoline in the New York area were cut to half an hour or less, according to the AAA.

Meanwhile, area station owners and police spokesmen said gasoline was somewhat easier and faster to get Sunday than during the last several weekends. The District and Maryland gave extra gasoline to 42 stations in the city and suburbs in return for a promise of Sunday openings.

Officials believe the crucial test for the metropolitan Washington area will come today with the resumption of the full workweek in the capital. Many residents were out of town on an extended Fourth of July holidays last week, when gas lines began showing improvement.

Under the odd-even gasoline purchase plan now operating in the region, only cars with odd numbered plates can buy gasoline today, when most station in the area are expected to be open. Lines are normally long early in the morning, but shorten as the morning wears on.

Yesterday, Prince George's "hot line" telephone operators said the average gasoline line in Prince George's was between 30 and 40 minutes long. "There were only a few stations with lines in which customers had to wait for an hour or longer. Most of these were those closet to the District," the attendant said.

Across the river in Virginia, the problem seemed to be one of finding a station that was open at all. Fairfax police said that as far as they knew only several Crown service stations in the county were open yesterday. Thirty-minute waits in two-block lines were common at the Merrifield Crown.

The six-block line at the Van Ness Gulf on Connecticut Avenue at 9:30 a.m. seemed more representative of gasoline lines in the District.

In Brentwood, Md., a Gulf station manager reported an hour-long line that lengthened as the day progressed and as other gasoline stations in the area closed. By 2 o'clock, the Brentwood Gulf was the only one in Prince George's County reported to be open.

At the same time, David Bardin, director of the Energy Regulatory Commission in the Department of Energy, said that a 50-state survey conducted by the Department last week, showed that several parts of Manhattan, "Washington, D. C., New Orleans, Baton Rouge (La.), and several smaller towns in Louisiana were the only place plagued by long lines." The survey defined long lines as those requiring waits of an hour or more.

Bardin could only speculate on the reasons. He noted that "part of the problem may be that the states have not given priority to their urban areas." Bardin said also that the fact that the District, Northern Virginia and Maryland don't use the odd-even system on weekends and don't make out-of-state vehicles play by the rules may have some effect on the length of gas lines.

In Louisiana there is no odd-even system Bardin said.

Already, though, there is some evidence that drivers in the metropolitan Washington area are beginning to venture out.

Brain J. Tidley of Vienna, who drove up with a small raft on top of his Chrysler station wagon and five family members in the car, said "Sure its a real hassle getting up at seven o'clock to go out and get gas, but we wanted to go to Virginia Beach and the only way we could make that possible was to come here and gas up."

Spokesmen for nearby resorts and attractions reported a sharp increase in the number of people arriving there over the weekend.

"The beach is peppered with people -- there are lots of people now on the boardwalk," said Elsie Kline of the Ocean City Chamber of Commerce. "We've got cars coming in here from as far away as Minnesota and Michigan. This is the best weekend in the past month or so. People are traveling now. They are not as frightened about not getting gas as they were earlier."

At Kings Dominion in Virginia, spokesman Tom Veazey said while attendance at the attraction had been "soft" since May, more people came this weekend than last weekend.

A park ranger at the Shenandoah National Park said last weekend was the first time since the beginning of the year that all campgrounds were filled. "Attendance is certainly up now," he said.

Evening Gasoline Hours

These District of Columbia stations will be open from 7 p.m. to 9 p.m. today through Friday with extra gasoline made available to them from the D.C. government's set-aside allocation:

Newnam's Teaxco, 5001 Georgia Ave., Nw

Mack's Service Station (Amoco), 801 M St., NW

Boulevard Gulf, 4885 Macarthur Blvd., NW

Rock Creek Gulf, 1827 Adams Mill Rd., NW

Yuen Exxon Service Center, 1800 Rhode Island Ave., NE

Anacostia Exxon, 2255 Martin Luther King Ave., SE

Douglas Heights Exxon, 2215 Alabama Ave., SE

Duvall's Sunoco, 3341 Benning Rd., SE

Telephone Help

Following are telephone numbers of agencies providing information to deal with gasoline emergencies:

District of Columbia "hot line": 628-3181. An official said it will be staffed from 9 a.m. to 8 p.m.

Prince George's County "hot line": 779-1151. An official said it would be staffed around the clock.

Bowie area gasoline hotline: 262-6262. It is scheduled to begin operation at 5. p.m. today. It will feature a recorded message listing names, locations and hours of gasoline stations.

Frederick County motel/gas hotline: (301) 663-8687 or 6622126. A spokesman said it is staffed 24 hours a day.

Anne Arundel County "hot line": (301) 263-2681. An official said it wuld be staffed from 6 a.m. to 9 p.m. daily.

American Automobile Association: 222:5000. Officials said AAA members may obtain small quantities of gaas or be towed to a nearby station if they are stranded.

Flag System

Washington area service stations have been asked to display special flags, noting the availability of gasoline.

A green flag means leaded and unleaded gasoline are available.

A yellow flag means only leaded gasoline can be purchased.

A red flag means a station's pumps are closed.

Gasoline station owners in the District of Columbia can pick up flags at the Munsey Building, 1329 E St. Nw, Room 1258. CAPTION: Chart, Daily Gasoline Guide, The Washington Post