The trouble started for Ellen Lemley as soon as the Metro deposited her at National Airport. Wearing a silk dress and loaded with luggage, she took a quick look at her watch and stared into the rainy distance.

"But this is a highway," she shouted at no one in particular. "I wanted to go to the airport."

Confronted for the first time with the bewildering maze of National Airport, Lemley shook her head and began the march from the Metro stop to the terminals.

National has caused many such headaches over the years. The transportation hub of the nation's capital, its facilities long have been overwhelmed by the people who use them. Makeshift terminals have sprouted like shanty towns, but they have not kept pace with the demands of 40,000 daily travelers.

"It is a major horror story of modern planning," said James Murphy, who until 1979 managed the airport and now is in charge of airport policy for the Air Transport Association. "You can't overstate the problems. It has the most severe facility constraints per square foot of any airport I have ever seen."

Few would disagree with him. There are almost 100 buildings serving more than 30 airlines packed onto National's 860 choice acres. Fewer than 5,000 parking spaces are available to the public -- and the best lot has been reserved for members of Congress. Without a place to wait for customers, taxi drivers simply take over the roadways. Arriving and departing passengers must use the same entrances. And the main terminal, designed in the 1930s not only for air commerce but also as a recreational showplace, lost its luster decades ago.

National is chaotic for several reasons. First, the federal government owns it, and improvements are subject to the scrutiny of Congress. The Federal Aviation Administration, which runs the airport along with Dulles International Airport, has had little success in persuading Congress to allocate more funds for the airports.

Although the Department of Transportation has said it would cost up to $750 million to refurbish National and expand Dulles, the FAA has in the past two years asked only for the money necessary to continue operations at the airports, about $10 million to $15 million.

Transportation Secretary Elizabeth Hanford Dole has worked hard to transfer National and Dulles from federal control to a regional authority that could raise revenue bonds to finance improvements. Her plan passed the Senate this spring but has met with an indifferent reception so far in the House. No hearings have been scheduled.

When National was dedicated by President Roosevelt in 1940, officials worried out loud that its graceful terminal and long runways were ahead of their time and that air traffic would not catch up for 50 years. But by the end of World War II, with the exploding demands of the air passenger industry, National was beyond its prime.

The year the airport opened, it served slightly fewer than 350,000 passengers. Today, that many people pass through there in a busy week, according to the FAA. The number would be even greater, but in 1981 the FAA imposed an annual ceiling of 16 million passengers as part of a policy that would help shift flights to Dulles.

Last year, 14.7 million people flew in and out of National, most of them willing to risk almost any temporary hassle for the permanent convenience of having a major airport only minutes from Capitol Hill.

"Now I know why they make suitcases with wheels on the bottom," said Dick Vass, a Richmond lawyer struggling to catch a plane that would take him to a reunion of his World War II Navy fighter squad. Vass was on his second trip from his parked car to the main terminal. "I took the big suitcase first," he said, taking a shortcut through the nearly empty congressional parking lot. "But I don't think you should have to make two trips from your car to get a plane."

Others greet their fates with less detachment. Negotiating the warren of seemingly unrelated terminals takes perseverance and luck. Passengers cite insufficient parking, an incomprehensible road system and lack of walkways between terminals. At rush hours, curbside logjams rival roller derby for ferocity because there are not separate entrances for departing and arriving passengers.

"They just lose control sometimes," said Robert Tyng, an FAA police officer who says his years at National have taught him to expect outbursts from even the most congenial people. "They start screaming and throwing their bags at me. People here will do anything. I have been bitten and I have been kicked."

Practically every attempt to improve facilities -- there have been dozens over the years -- has been met with hostility. Local residents opposed to the nearby noise have for years attempted to close the airport and divert its traffic to Dulles. They have fought repeated attempts to add parking, build a passage to link the Metro stop with the North Terminal and renovate the dilapidated terminals.

The National Capital Planning Commission, which has an advisory role in the planning of federal facilities in the Washington area, also wants to eliminate the airport, saying that "it should be phased out as a major commercial airport at the earliest practical time."

The commission and others have always opposed improving facilities at National, apparently on the theory that if using the airport is made traumatic enough people will eventually give up.

"It's just not socially correct to come out and say I like Washington National," said James A. Wilding, director of the Metropolitan Washington Airports, which runs National and Dulles for the FAA. "People tangle up the issue of preventing growth at National with allowing basic improvements here."

The result is apparent to anyone who visits the airport. Almost every rush hour finds cramped commuters jostling each other to get into a bathroom. Limited counter space for airlines means that ticket lines are usually long. Even the slot machine television sets for travelers are overburdened and old-fashioned.

The last building to be completed at National was a new firehouse in 1982; the last terminal completed was the Piedmont Airlines terminal in 1973. And while the number of annual flights has not increased significantly in 15 years, the total number of passengers crowding into the terminals has grown from 11 million in 1973 to almost 15 million this year.

"The problems here are issues beyond the control of management," said Edwin I. Colodny, president of USAir, which has its sparse corporate headquarters in one of the oldest hangars at the airport.

In a recent letter to Rep. William Lehman (D-Fla.), chairman of the House subcommittee on transportation, Dole estimated that even the most minimal renovations at National would cost more than $100 million. Airline industry executives -- who are eager for the transfer and the improvements -- say the figure could be far higher.

Master plans to improve the airport are devised, discussed and rejected. Because of the history of opposition, a master plan study under way for the FAA is being treated as if it were a top government secret.

"If we say we would like to provide a terminal with some decent bathrooms, people start to moan," said Saul Jacobs of Howard, Needles, Tammen and Bergendoff, the consultants hired by the FAA to revise the master plan. "If somebody buys a ticket, we think that person is entitled to a minimum level of comfort."

Safety also has been a major concern at National, largely because the airport lies so close to Arlington County, Alexandria and the District. The Air Line Pilots Association has in the past been vocal about poor visibility and short runways at National, but recent FAA improvements to the runway system have satisfied many of their complaints.

Some have charged, however, that PortAmerica, the recently proposed 52-story trade center in Prince George's County, would pose new danger to planes headed for National. The FAA is studying possible effects the building may have on air traffic.

The location of the Metro stop is often taken as a symbol of the ineffective planning that has plagued the airport. Ten percent of all passengers to the airport get there on the subway, but because not enough funds were allocated to run the line closer, people have to walk up to a half-mile across the main road between the terminals and the station.

The FAA would like to enclose that walk or use a people mover but does not have the funds. For now, there are shuttle buses, which many passengers choose to ignore.

"It is a significant disgrace," said Murphy, who as airport manager fought first to bring the Metro to National and then to try and get it to run to the terminals. "The Metro created a wall that breaks the airport in two. It was a fine opportunity lost."

FAA plans for multilevel and underground parking garages have been put on hold, as have plans to refurbish the Main Terminal and replace the North Terminal with a modern building that would connect to Metro by underground passages. The cost of those improvements -- considered essential by DOT -- would be at least $65 million. Creating a road system that segregates taxis from other traffic and divides arrivals from departures would cost up to $20 million.

"There really isn't much we can do about it unless the transfer goes through," said Wilding. "It's not that these things are impossible to accomplish. But the airport has been neglected for so long, many people have grown used to it. There are times when I see people out there that have obviously never been to Washington before. To those people I can only say I'm sorry."