Here’s the problem: Seattle-Tacoma International Airport’s passenger and freight traffic is growing faster than anyone had projected. The airport, which handled nearly 37.5 million passengers last year, a 7.7 percent increase, is close to running out of gates needed to handle flights arriving at the airport.
But the airport site, at just 1,500 acres, is one of the tightest of any major hub airport in the country. While newer hubs such as Dallas-Fort Worth (17,400 acres) and Denver (34,000 acres) have ample room to stretch out, Sea-Tac’s site, which seemed more than ample when it opened to commercial traffic in 1949, is running out of room for new facilities.
According to Sea-Tac officials, the airport handled 23,200 passengers per acre in 2013 compared with other older urban airports, such as in Boston (18,880 per acre); Newark, New Jersey, (20,590); and Las Vegas (17,040 per acre).
In a memo to Port of Seattle commissioners, Sea-Tac director Mark Reis explained why additional airport expansion is a priority issue:
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“The city of Seattle had the highest rate of population growth of large U.S. cities in 2013 and the Seattle-Tacoma International Airport was the fastest growing large hub airport in the U.S. in 2014. In addition to providing jobs in the local community, the airport is a critical regional and national asset connecting the region to the global economy. The airport requires adequate infrastructure to fulfill its mission as an economic engine and enable the region to maintain its competitive edge. Due in large part to a strong regional economy and projected slight decline in airfares over the long-term, airport activity is projected to reach 66 million annual passengers and 540,000 annual aircraft operations by 2034. Strong near-term growth and significant increases in peak hour aircraft operations, passenger volumes and vehicles on the roadways presents formidable facilities planning challenges.”
The Port of Seattle is deep into planning near-term expansions, but those won’t be enough to handle the estimated 66 million passengers projected to use the airport in 2034.
Two expansions are close to beginning: A new International Arrivals Facility at the airport’s south end and remodeled and expanded North Satellite Terminal on the north side.
The International Arrivals Facility will create an overhead passenger bridge connecting the present South Satellite Terminal with a new International Arrivals Facility to be built adjacent to the present A Concourse. It will increase the processing capacity for international passengers by 60 percent and increase the number of international gates from the current 11 to 18. The new facility is scheduled to open in early 2019.
The North Satellite project, which the airport calls NorthStar, will expand the North Satellite from its existing 12 gates to 20, more than double the space for vendors and restaurants, create a rooftop lounge for Alaska Airlines’ elite passengers and bring the whole facility up to date. The terminal will become the center of Alaska Airlines’ passenger activity at Sea-Tac. The overhaul and expansion is set for completion in the summer of 2020.
Those expansion projects won’t be in place quick enough to handle the anticipated traffic next year. The airport might have to create remote gates served by buses or a temporary lobby for check-in for those temporary gate positions.
“The situation is likely to get worse before it gets better,” said Sea-Tac spokesman Perry Cooper. “With new international flights being added, the midday arrivals will exceed the number of gates we have to handle them.”
But beyond those projects, the airport will have to grow even further to keep up with passenger growth.
Here’s what the airport says it will need in two decades in addition to the facilities debuting in the next five years:
• Thirty-five gates for domestic traffic.
• Nine gates for international, wide-bodied airliners
• Expanded terminal check-in, security screening, baggage handling and retail facilities.
• An automated system to move passengers to remote gates and concourses.
• New taxiways and runway bypasses to handle 120 landings and takeoffs per hour. The airport capacity is now 88 an hour.
To accomplish these objectives, the Port of Seattle Commission is expected to decide this year how best to fulfill those needs.
Among the choices:
• A new terminal north of the existing North Satellite. The terminal would occupy land now a Doug Fox airport parking lot. Or an additional expansion of the North Satellite.
• A second South Satellite Terminal or a long dogleg extension of the existing A Concourse. A satellite terminal would require lidding over South 188th Street south of the airport.
• Expansion of the present main terminal to the north and to the east. The eastward expansion would require moving the present airport drives into the airport parking garage.
• On the airfield side, the airport would have to construct more parking areas for aircraft stored overnight and more queuing space for those aircraft awaiting takeoff. The airport is considering building taxiways around the ends of the existing runways to keep aircraft headed for the second and third runways from blocking the eastern-most runways when crossing.