It's 9 a.m. and the parking garages at Denver International Airport are already filled to capacity, as are the economy spaces and the main shuttle lot.
The crowds at the airport's two main security checkpoints curl around the roped cues, spilling into the terminal and snaking past the baggage carousels.
There is little relief on the other side of security.
Lines 20-people deep branch out from concourse restaurants and fast-food stands, and passengers are sprawled on the floors near the packed gate areas.
This was the scene at DIA on a Saturday in August, but it isn't limited to just this one morning.
There have been plenty of days like this in recent months.
Twelve years after handling its first flight, DIA finds itself at a critical juncture, bursting at the seams with passengers, scrambling to keep pace with breakneck growth and edging closer to its maximum capacity.
"I'd say at least once or twice a week we're filling up our parking lots, and we have to open the overflow" shuttle area, said DIA Manager Turner West. "That used to be rare. It's just one example of how the system is stressed. It's not just parking. It's security and roads and gates and concessions."
To address its rapid growth, DIA is undergoing a comprehensive review of its long-range master plan and has launched numerous expansion and improvement projects to ease congestion in the near term. It plans to spend more than $1 billion through 2013 on its concourses, concession areas, security checkpoints, parking lots and baggage system.
But it's a daunting task, especially in a volatile, vulnerable industry fraught with unpredictable swings in demand and financial instability.
The airport's success in keeping up with growth - and keeping a lid on the fees it charges airlines - is vital for the region because it will affect everything from airline service to economic development. It's also of the utmost importance to travelers, many of whom have come to depend on moving through DIA quickly, efficiently and, in recent years, cheaply.
"The risk of doing it wrong is that Denver's future growth will be threatened," said John Kasarda, a management professor at the University of North Carolina at Chapel Hill's business school who has studied airport growth. "The community has to know that the livelihood of the entire state is based on air travel. The airport is the lifeblood of 21st century metropolitan economies."
Surprising growth rate
It wasn't that long ago when DIA felt cavernous.
It rarely was difficult to find a parking space in 2003. Security lines were almost nonexistent. And you easily could find a seat in the gate areas.
So what happened?
The burgeoning passenger numbers caught airport and city officials by surprise.
DIA's original master plan outlined a rough blueprint for growth until the airport hit about 50 million passengers annually, when it would have to consider a major expansion phase.
The airport had posted solid passenger gains throughout the late 1990s, but the 2001 terrorist attacks brought that to a grinding halt.
Traffic and airline operations (takeoffs and landings) at DIA fell to 1997 levels. United Airlines tumbled into bankruptcy, throwing the future of Denver's largest airline into doubt. Demand slumped nationwide, and some observers predicted it would take many years to get back to pre-2001 levels.
DIA had to shelve most of its expansion projects because the uncertainty was too great.
Demand, though, began a steady march upward in 2003, and by the end of the next year DIA was setting passenger records. Homegrown Frontier Airlines fueled much of that growth, gaining market share and adding flights and destinations while its larger competitor United cut back.
Airport officials, though, thought it still would take years to hit the 50-million mark.
The expansion would involve extending the east end of the concourse by a couple of hundred yards.
The eight-gate expansion, expected to take about three years, needs approval from the Denver City Council.
DIA will spend $41.5 million to upgrade and expand United's regional jet facility on the east end of Concourse B. The airport also will pay off $110 million in debt related to United's failed...