Roughly 20 major US airport expansion programs worth about $75 billion have run over the past decade, and the logic behind the next wave has shifted: airports now design for operational fit and resilience rather than raw gate count.

Dave Dague, a principal in Arthur D. Little's Travel & Transportation practice, advises airports on air service, economic impact, public-private partnerships and long-range forecasting. In an interview with Airport Business, he laid out how the planning calculus has changed since COVID — and why the structural gap between infrastructure timelines and industry change keeps widening.

From capacity to customer experience

Two decades ago, airport development asked one question: how many gates and how much capacity. "Now it's about making sure we're building an airport that fits the operation," Dague said. That means access, processing time, security, concessions, dwell time and resilience — including how a facility performs when weather disrupts airline operations.

Kansas City illustrates the shift. Its three unconnected round terminals from the 1960s were demolished and replaced by a single central facility that processes passengers through one building. The objective is efficiency on both ends: move passengers quickly, and capture non-aeronautical revenue along the way. "The goal is to get you in and out as efficiently as possible, but it's also to get you to buy that Cinnabon with extra icing," Dague said.

The premium-travel surge reinforces the trend. Ultra-low-cost carriers, once a significant share of the industry, have contracted; airlines now segment cabins into differentiated experiences, and Dague expects further segmentation. Whether the premium market saturates — and whether the ULCC model returns — remains an open scenario for terminal planners.

The US-Europe operating gap

Most US airports are run by municipalities or government agencies that control the terminal but not the full ground operation. European and Asian airports often control more, including ground support and baggage handling, which Dague argues produces measurable efficiency gains. He cited Edinburgh as an example that struck him on a recent transit.

"I look at U.S. airports as two experiences," he said. "You have the airport experience and you have the airline experience. One you can control and the other you can't." Many US airports benchmark European peers on operations down to details like signage.

Passenger mix shapes the asset

Network role drives design decisions. Atlanta processes a large share of connecting traffic; New York, Philadelphia, Boston and Los Angeles serve predominantly origin-and-destination passengers, and their terminals foreground local identity through restaurants and concessions. The airport is, for many arrivals, the first view of a city — a consideration that extends to smaller fields competing for return visits.

Airlines hold the leverage in expansion economics because they fund it through use fees. That disciplines scope. "They don't want the Taj Mahal," Dague said. "They don't want a facility with 12 unused gates. The facility needs to be used."

Carriers share five- and 10-year growth plans with airports, but selectively. If one carrier expands and takes market share, another may shrink — a dynamic airports must model without full visibility into airline strategy. Dague described airlines as "very coy about their future plans," while noting that coordination between the two sides is substantial.

Forecasting as scenario planning

Any expansion forecast requires FAA review and approval, typically built as low, mid-range and high cases extending 20 years. Those frameworks hold until an external shock — COVID being the canonical example — invalidates the assumptions. Forecasting, in Dague's words, "has become an art."

The models draw on income data, economic demographics, airline projections, capacity changes and traffic composition — domestic versus international, connecting versus local. Aircraft are getting bigger, which changes seat capacity per gate movement. Planners can stress-test scenarios against historical shocks, from 9/11 to the pandemic, because the industry retains a long data history.

Two constraints frame the next decade. First, delivery shortfalls at Boeing and Airbus have suppressed capacity growth; when output recovers, competition could intensify again and alter traffic assumptions. Second, large-hub airports face physical limits on expansion. Seattle has discussed growing up rather than out, and Dague expects airports to get creative with constrained footprints — communities want better airports, not necessarily bigger ones.

Technology sharpens the demand side of planning. Airports can now track traffic and passenger journeys in ways previously impossible, and more of them are actively analyzing who their customer is rather than simply processing whoever arrives. Dague cautions that the data pool includes as much bad information as good, and that analytics have limits: AI can model passenger behavior, but "it's not going to help us pour concrete any faster."

The core planning problem, as he frames it, is temporal: the horizon for building infrastructure is longer than the time it takes the industry around it to change. Airports that once optimized a single touchpoint like concessions now design the entire journey — curb, security, processing — because, as Dague put it, one little blip can ruin it. How the industry plans for a future it is uncertain about will determine whether the next $75 billion in projects buys flexibility or stranded capacity.