Unpredictable security lines. Frequent flight delays. Cutbacks in on-flight meals.

Bad news for travelers, but a windfall for Washington area airport retailers.

A crush of post-9/11 security measures, which has convinced travelers to show up hours before takeoff, and the dominance of discount airlines, which encourage fliers to pack their own food, is turning airline passengers into potential cash cows who spend more time and money than ever inside airports.

Retail, food and beverage sales at the region's three airports are up 9 percent since 2001, with average per-passenger spending rising to $6.34, as bored travelers with time to kill splurge on gifts for family, clothes for work and sandwiches for hours-long flights on cost-cutting airlines.

Larry Sluder, a Florida consultant, arrived an hour early for a 4:49 p.m. flight home at Reagan National Airport last week with no intention of spending a dime in the terminal. Then came a delay that would mean missing a connecting flight in Cleveland.

So he left the secure gate area, rebooked on a 7:30 p.m. flight and used the extra time to buy a shirt at the PGA store and dinner at Legal Sea Foods before submitting to a full-body pat-down.

His total time at the airport: 3 hours, 40 minutes. Total spending: $28.50.

The increased spending is not spread evenly across the region's airports. National, with its mall-like central terminal, is the undisputed retail leader, with the average traveler spending $8.32 per plane ride last year, according to Airport Revenue News, an industry trade publication.

That compares with $5.65 per passenger at Baltimore-Washington International Airport and $5.05 at Washington Dulles International Airport, where spending has fallen slightly since 2001.

The reason for National's success: After struggling in its infancy, the Cesar Pelli-designed main terminal has been fine-tuned into a successful shopping center, with a mix of gadget-filled shops for business travelers (PalmOne) specialty stores for tourists (WomenRock) and sit-down restaurants for anyone with time to spare (Matsutake offers Japanese cuisine).

Dulles and BWI are reinventing their retail lineups by adding the kinds of stores and restaurants behind National's success, airport managers said.

In Concourse B at Dulles, expanded in 2003, Fuddruckers Express, Matsutake sushi and a sit-down Harry's Tap Room restaurant are planned for this summer, joining a new Villa Pizza, a massage station, and In Motion Entertainment, a CD and DVD store.

Dulles's three other concourses are scheduled for retail overhaul modeled on Concourse B. "Passengers expect more than what's here now," said Colleen Van Hoene, who manages concessions at Dulles.

The biggest challenge at Dulles: finding space for new retail. Passenger traffic increased 35 percent in 2004, and the airport's inability to expand retail hurt its sales, said Tara Hamilton, a spokeswoman for the Metropolitan Washington Airports Authority, which runs Dulles. Longer lines at concessions discouraged buying, dragging down spending, officials at the authority said.

BWI retail is managed by BAA USA Inc., a subsidiary of BAA PLC of London, which pioneered the mall-within-an-airport concept at Pittsburgh International Airport. That airport's retail sales are the highest in the country, according to Airport Revenue News.

In Concourse A-B at BWI, built for Southwest Airlines, there are several new restaurants, including local chain Phillips Seafood, Quiznos Sub, Charlie Chang's, California Tortilla and Church's Chicken. There are also two locally based retailers on the concourse, jeweler Fire & Ice and men's clothier Jos. A. Bank.

The Jos. A. Bank Clothiers store at BWI is the chain's first in an airport -- and a potentially risky test of a new market. David E. Ullman, the retailer's chief financial officer, said the store's location behind security checkpoints gives it an edge because its core customer, a business traveler, is arriving earlier then ever.

But there are challenges. An airport location means a smaller store -- 1,000 square feet, vs. 4,500 for a normal store -- and cutting out 80 percent of its typical stock of merchandise. "We don't have big and tall shirts," Ullman said.

There are also longer hours. The Jos. A. Bank store at BWI is open from 5 a.m. to 11 p.m., increasing labor costs.

The new emphasis on airport retail is a far cry from just two decades ago. Airports considered shopping an afterthought, shoehorned into strangely shaped spaces left over after architects accommodated planes and people.

That changed in the early 1990s, when airports in Pittsburgh and Portland, Ore., opened extensive shopping centers inside their terminals, quickly dubbed "airmalls." National's renovation and reopening in 1997 delivered a scaled-down version of the concept, but Dulles and BWI remained constrained by space and design.

Dulles's main terminal, for example, which is separated by "mobile lounges" from passenger gates, was designed with minimal retail, even though thousands of hungry people stream through it every day.

For all the changes, travelers at area airports complain that they still can't find the food or shopping options they want after passing through security checkpoints.

Frank Horvath called the dining options near his gate at Reagan National Airport -- such as Ranch 1, Cinnabon and Primo Cappuccino -- "extremely limited."

Over at Dulles, Carnie Stankiewicz described the food on her concourse -- including Villa Pizza and California Pizza Kitchen -- as "slim pickings."

David R. Stone enjoyed his Au Bon Pain sandwich at Baltimore-Washington Airport, but was not satisfied with the coffee. "I want Starbucks," he said.

Airports managers say expanding post-security retailing is a major challenge given space constraints. At National for example, there is simply no room to expand gate-area dining and shopping.

Then there are the potential shoppers who never cross security checkpoints -- the family, friends and co-workers who pick up arriving passengers at the region's airports. The quality and quantity of retail options for them vary widely.

At National, they can sample a variety of stores and restaurants. But at BWI and Dulles, they are largely out of luck. Megan Bowman spent 20 minutes hunting for a bottle of juice for her 11-month-old child while waiting for her sister to arrive in the Dulles baggage claim area. When she eventually found one, the store would not accept her credit card. So she gave up.

"There needs to be more options," she said.

Dulles and BWI are trying to put sit-down restaurants in pre-security sections.

The main terminal at Dulles "was not designed as a place to linger," said Van Hoene, the concessions manager. "But now it is and we need more retail."

All three airports say their retail prices are comparable to those outside the airport, a policy known as street pricing. The airports monitor pricing with regular spot checks and advertise the policy in signs across the terminal. There are phone numbers to call for customers who suspect they have been overcharged.

Not everyone thinks it's working. Michael Puzzo, 35, a sales executive from Newark, N.J., bought a one-liter bottle of water at Dulles for $2.40. "You can buy that in the grocery store for 99 cents," he said.

Reagan National Airport has the most retail stores of the region's three airports. BWI and Dulles are trying to catch up.BWI's new Southwest terminal includes several food concessions.