DCA is facing challenges due to the need to accommodate increased use, baggage and security. The design of the airport requires 3 security stations because there isn't a single central terminal leading to the gates. (Astrid Riecken/For The Washington Post)

Sometimes it’s the little things that tell the larger story, like the sign about 40 yards from the security checkpoint at Reagan National Airport.

“Not much longer,” it cheerfully tells passengers as they snake toward the Transportation Security Administration scanners. “25 min approximately from this point.”

A lot of people get to see that sign — more than ever before — as Washington’s tiniest commercial airport is morphing into something it has never been and was never intended to become.

Squeezed by the Potomac River on one side and Arlington County on the other, National has endured for six decades as a destination airport: Fly in, fly home. Now, with no room for growth, it is growing nonetheless, becoming a mini-hub airport for an airline industry that has been transformed into a transcontinental network of hubs.

The new role as transit point has meant larger planes, more passengers and tons of additional luggage. Added to that, its most regular passengers — members of Congress — have insisted on new flights to the more distant cities that some of them call home.

“It’s a dramatic increase in passengers,” said Paul Malandrino Jr., the airport’s manager, as he breezed through the concourse this past week. “As an airport manager, that’s a good problem, but it’s a problem.”

It’s a good problem because the Metropolitan Washington Airports Authority runs Reagan National and Dulles International off proceeds from the airlines and airport concessions. It becomes a bad problem if passenger frustration grows while Malandrino’s team rushes to make “Band-Aid” fixes and calculates how best to achieve and pay for what is really needed.

In July, there were 75,465 more passengers passing through than in the same month in 2011. Last year, before many of the new flights were added, the passenger load increased by 704,381 over 2010. That has put the squeeze on baggage handling, parking, security and simply managing passenger flow.

Take one example: Virtually every modern hub airport is configured to let arriving passengers reach gates for connecting flights without going through security again.

As a destination airport, National never needed that web of connecting walkways on the secure side of the checkpoints. So, when more than 40 percent of arriving US Airways passengers began heading for connecting flights (a recent increase from 18 percent), the airline started offloading those people directly from the plane onto a bus that carried them to their flights in an adjoining concourse.

This is inconvenient and it’s not pretty in the rain or snow, but the alternative is sending them into the main concourse for another trip through a “Not much longer” security line before boarding flight No. 2.

With overall passenger numbers at National setting a record this summer, those checkpoints have become choke points during the busiest times. One of those peak-load hours is a subtext to the narrative that makes National unique — when Congress goes home for the weekend on Thursday afternoon, the place is mobbed. And unless they are traveling with a security detail, your senators and representatives stand in line like everybody else.

“Frankly, it’s a pain in the butt,” said Rep. Tom Petri (R-Wis.), who seeks no special treatment just because he heads the House subcommittee on aviation. He estimates that he passes through National 60 times a year.

National’s evolution from destination airport to one where many passengers touch down just long enough to change planes reflects an industry transition that has been underway for decades.

Every major airline has hubs from which commuter planes fly to smaller cities. Think Chicago, Dallas, Newark, Atlanta, Phoenix, Minneapolis and Baltimore. If you fly often, the mention of those airports probably will conjure up the name of the airline that dominates them. No one has formally declared National as a hub, but US Airways and JetBlue have taken the lead in establishing it as a transit point.

Passenger growth

Though National is distinctive in some respects, the airport’s predicament reflects a looming problem in U.S. aviation. The government and airlines have embarked on an investment of about $40 billion in a revolutionary air navigation system to accommodate expectations that air travel in the United States will grow by 265 million passengers in the next dozen years.

The Federal Aviation Administration projects that passenger traffic at commercial airports will more than double in two decades. Moving along all those additional planes and passengers on the ground poses a $19 billion problem, according to the American Society of Civil Engineers.

That is how much additional investment is needed in airport expansion if already congested airports are going to be able to meet demand by 2020, the ASCE said in a report this month. Extrapolating from FAA data, the report said the already hefty cost of airport delays could rise to $34 billion a year by 2020.

For some major airports on the fringes of urban sprawl — Dulles and Baltimore-Washington Thurgood Marshall International among them — there is room for physical expansion. Finding the cash to pay for it is their big issue. But a lot of others, like 860-acre National, Chicago’s Midway, New York’s LaGuardia and Boston’s Logan, are hemmed in by the cities that surround them.

The number of flights at National, LaGuardia and the two other airports that serve the congested New York area— John F. Kennedy and Newark — are dictated by the FAA.

The Government Accountability Office this month concluded that National had enough runway capacity to handle new flights demanded by Congress but that the “terminal and land side facilities are more constrained.”

Though the local airports authority runs National, the federal government was in charge until 1987 and still determines how many flights should be allowed there. Congressional bickering over new slots that members demanded to ease their commute home was one of three things that held up an aviation funding bill last year and led to a partial shutdown of the FAA.

The old rules said National should not provide service beyond a 1,250-mile domestic radius, but Congress has bent those rules to add 14 longer round trips to Austin, Denver and several West Coast cities. The GAO estimated that flights to eight new destinations Congress added this year may carry as many as 1,245 new daily passengers.

The attraction of National for folks on Capitol Hill and most of the airport’s local passengers is obvious.

“I love that it’s close,” said Janet Kubalak. “For those of us in the city, it’s easy to get in and out of. Like a local airfield.”

It’s smaller and easier to navigate, said David Hartogs. “You don’t have to walk far to the gates.”

And it’s convenient, said Kevin H. Posey, chair of the Alexandria Transportation Commission.

“I timed a trip from arrival at Atlanta to my car in the parking lot at one hour,” Posey said. “At National Airport, I can reach Metro or my car in 20 minutes. That is, unless I check my bag. National’s baggage handling is notoriously slow.”

Malandrino is working on the baggage issue, one of several short-term fixes he has underway. Terminal A, which serves Southwest Airlines, JetBlue and several other carriers, is about to get a new adjacent building for most outbound baggage. JetBlue, which has seen its baggage volume increase by 70 percent recently, will get an expanded conveyor belt on the concourse level and a larger area one floor below.

Terminal A is the airport’s oldest, and its banjo-shaped pier causes a bottleneck. That corridor is to be widened, adding another security checkpoint.

On the taxiway just outside the banjo, new asphalt has been poured to repair ruts that formed when heavier planes began pulling up to its gates.

The three piers in the newer B-C terminal also will get upgrades. Things are being shifted around at the south pier (gates 10 to 22), the airport’s most busy, to open up another security checkpoint.

Commuter planes, which park just outside the north pier, are often bigger and heavier, so steel plates have been installed under the asphalt to support them.

The airlines also changed the playing field at National by swapping slots at different airports to consolidate their efforts.

Though the economy parking lot has filled to capacity 60 times this year — twice as often as in all of 2011 — there is not much space for expansion. National added 1,400 spaces to the daily garage two years ago, making room for 7,000 vehicles in the two facilities.

Bigger issues, such as getting people who are making connections from gate to gate without making them board a bus or go through security again, will be something for the airport authority to tackle once the immediate issues are addressed.

“At Dulles, we recruit new air service,” authority spokesman Rob Yingling said. “Here, they find us.”

“No, we definitely do not recruit here,” Malandrino said.

Then and now

Before there was National, the nation’s capital was served by Hoover Field, judged to be one of the worst airports anywhere. Pilots had to dodge radio towers in Arlington and an amusement park next door, deal with smoke from burning rubbish at a landfill on the other side, and be on the lookout for children who crossed the landing strip on their way to a public swimming pool. There also was a road that ran across the airport. In 1928, a plane crashed into a car left parked on the runway.

By then, Hoover was handling almost 2,800 flights a month, and in June of 1928 a record was set with 4,200 passengers. President Franklin D. Roosevelt got fed up with it all and said a new airfield should be built on the Potomac River mud flats known as Gravelly Point. A few years later, the Pentagon would open where Hoover Field once sat.

Other than the fact that most of it was under water, Gravelly Point was an excellent location for an airport to serve Washington, providing easy access and a splendid view of the capital city. A dike was built to keep out the Potomac, and almost 20 million cubic tons of sand and gravel were pumped in behind it.

In 1942, its first full year of operation, National Airport handled 77,348 flights and 459,396 passengers. Last year, commercial flights numbered 275,512 and the passenger count was 18,823,094.