Thousands of Washington area residents-jittery over the availability of gasoline-are apparently reevaluating their vacation plans with an eye toward longer visits at resorts closer to home.

Resort operators and tourism officials in a 200-mile radius around Washington say that advance bookings are gunning well ahead of last year and that gasoline supplies outside of Washington are more secure.

The uncertainty has caused the operators of relatively nearby vacation spots to dust off "One Tank Away" promotional materials they stowed away after the passing of the 1973-74 fuel shortage.

Glenn T. Lashley, an official with the Washington branch of the American Automobile Association (AAA), said that his organization "has received hundreds of calls from families who are afraid that if they take long distance automobile trips, they will be stranded on highways because of the fuel shortage."

"We are telling them there is no reason to panic," said Lashley, who echoed the caution of federal energy officials that spot shortages forecast months ago-due primarily to cutbacks in Iranian oil production-will not be severe if motorists resit topping off their tanks at every opportunity.

Nevertheless, widespread weekend closings by gas dealers trying to stretch monthly allotments from oil companies are fforcing area residents "to do a better job of planning . . . maybe by finding a vacation spot closer to home and using public transportation," said Lashley.

Conversely, out-of-town residents planning to come to Washington for vacations are facing an equal uncertainty.

For instance, Jon and Karen Clapp of Lake Orion, Mich., have been planning a trip to Washington with their two daughters for about a year. "But when we read of the projected (gasoline) shortage over the Memorial Day weekend in this area, we had no idea what it would be like there (in Washington.)"

Last week, Mrs. Clapp wrote to the Washington office of her local congressman, who in turn contacted the AAA office.

The message she received back was that gasoline "should be available on the expressways, but it was sort of iffy in the Washington area." She said she was also told not to bring the family car into Washington, but to "stick to the subways and the tourmobiles."

The Clapps are still planning to come to Washington, but the big devision facing them now is whether to drive the family Pontiac, which gets 17 miles to the gallon on regualr gas, or pack the family of four into a Chevy Vega, which gets 26 miles to the gallon on unleaded gas.

"It would be harder because the Chevy doesn't have air conditioning. It's sort of a flip of the coin . . . we think if there's going to be a shortage, it might be unleaded," Mrs. Clapp said.

In the meantime, Washington residents are being courted enthusiastically be nearby beach and mountain resort operators.

For the past several weeks, Harry Kelley, the mayor of Ocean City, Md., one of the most popular seashore spots for Washington residents, has vowed repeatedly that if anyone gets stranded without gas in his city, "I'll get'em home."

Kelley, known for his irrepressible boosterism on behalf of Ocean City, says he has developed a "genuine plan" for providing a sure trip home for stranded tourists.

However, he said, he will not reveal any details of the plan. "That's my secret," Kelley said.

Gary Fisher, director of the Ocean City convention and visitors bureau, said that advance bookings for the more than 19,000 cottages condominiums and hotel and motel rooms on the beach are running 13 percent ahead of last year's record figures.

"Because of the uncertainty of the availability of gas, it appears that people are travelling closer to home for longer periods of time," said Fisher.

The Rev. Bernard Deutsch, a member of the Ocean City Council, said gasoline retailers report no shortages. "There's been no panic buying down here."

At Virginia Beach, 214 miles, or 7.7 gallons of gasoline to the southeast of Washington at 20 miles per gallon, 30 percent of the calls on a toll-free tourism hotline have been inquiries about the availability of gasoline, according to James Ricketts, the city's tourism coordinator.

Ricketts said gasoline supply "is a little tight in Virginia Beach, but there are stations open on the weekend." He said that city officials have met with gas dealers who pledged to keep some stations open on the weekends on a rotating basis "unless it gets really critical."

During the 1974 shortage, Ricketts said, listings of gas stations operating hours were provided to hotel and motel operators who passed the information on to their guests. "If things get a little more serious, we'll do that again," said Ricketts.

A third of Virginia Beach's vacation trade comes from Virginia and the Washington metropolitan area, Ricketts said. "Our advance reservations are extremely good. We have a big advantage because we're so close to the heavily populated areas. As long as gas is available here, they (vacationers) can get back."

Aside from the Atlantic beaches, dozens of vacations resorts lie within the cruising range of a single tank of gas - from the rolling parkland of Valley Forge 150 miles to the northeast to the Gettysburg battlefields south to Antietam, Harpers Ferry and the Blue Ridge mountains of Shenandoah National Park 72 miles to the southwest.

At Harpers Ferry, W. Va., 64 miles to the northwest, D.C. (Dixie) Kilhum runs the Hilltop House Hotel, which overlooks the confluence of the Potomac and Shenandoah rivers.

"There's no problem with gas at all up here," said Kilhum. Should there be a problem in the future, however, "we anticipate the train to help a lot," he said. referring to Amtrak's Blue Ridge line, which makes daily and weekend runs to Harpers Ferry.

Kilhum said he has heard the talk that resorts close to Washington will do a better business this summer. "They say that we'll do better because people want to come somewhere (and) they'll come to us because we're close," he said adding, "I don't know, I hope so. We do not expect, frankly, to make money this year because of inflation and all these things going on."

A spokesman for the West Virginia tourism department said most gas stations in the state are closing on Sunday and many are closing in the early evenings during the week.

State officials have begun to meet with retail gas dealers to extract a commitment to keep some stations open on a rotating basis. CAPTION: Map, Vacation Spots on a Tankful of Gas, By Dave Cook - The Washington Post