BOSTON — The next time thunderstorms rumble across Boston Logan International Airport, travelers may want to brace for a long wait. New research from Harvard University indicates that the odds of being stuck on the ground for at least three hours are now four times higher than they were in the early 1990s. The analysis, which combs through more than 30 years of federal flight data, paints a sobering picture for anyone planning to fly through Boston or any other major U.S. hub.
Harvard crunches 100 gigabytes of flight delay data.
Maxwell Tabarrok, a doctoral candidate in economics at Harvard Business School, sifted through 100 gigabytes of statistics from the Bureau of Transportation Statistics to understand why his parents recently found themselves stranded for hours at Logan. What he discovered is that severe, three-hour delays have crept steadily upward across the National Airspace System. “Airlines made a decision to start padding their schedules,” Tabarrok said, as Tabarrok told Fortune. According to his calculations, carriers have tacked on an average of 20 extra minutes to published flight times since 2000. The result is a statistical sleight of hand: an arrival that is no faster in real life can still show up as “on time” in federal performance reports.
Padding masks the economic cost of delays
By contrasting scheduled gate-to-gate times with actual wheels-up and wheels-down timestamps, the Harvard study estimates that Americans collectively forfeit roughly $6 billion in personal time each year. The figure is based on average U.S. wage rates—an eye-opening reminder that every minute idling on a taxiway has a price. Tabarrok’s timeline shows the divergence began after 2000. From 1987 through 2000—15 years—the gap between scheduled and real flying time stayed narrow. Once airlines began adding buffer, the two lines veered apart, obscuring a mounting reliability problem.
More passengers, same infrastructure
Part of the strain comes from sheer volume. Passenger traffic has swelled about 50 percent since 2000, yet the United States has not opened a new major commercial airport since Denver International debuted in 1995. Runway construction at existing hubs has also been minimal, leaving more aircraft to jostle for the same stretches of pavement. Larger jets, introduced to absorb the demand, compound the congestion: they board slower, unload slower, and occupy gates longer.
Controller shortages and outdated tech
Inside the control tower, an ongoing shortage of certified air-traffic controllers limits how many airplanes can move through crowded airspace. Recent Federal Aviation Administration equipment outages have added to the stress. Weather remains the single largest non-airline factor, but Tabarrok argues that stronger staffing levels would make the system more resilient when storms or mechanical hiccups ripple through major hubs like Boston. In a statement, the FAA said, “safety sometimes necessitates delays.”
Why incentives matter
Tabarrok contends that the underlying problem is misaligned incentives. Because the FAA does not directly bear the expense of delay—nor do its employees earn bonuses for smoother traffic flow—the agency has little reason to push aggressive reforms, he says. Meanwhile, airlines have every motive to tweak schedules to dodge federal penalties for poor on-time performance, even if the passenger experience deteriorates.
Can infrastructure keep pace?
Long-term fixes, such as new runways, face environmental reviews and legal challenges that can last a decade or more. The absence of major airport construction since 1995 suggests travelers should not expect physical capacity to expand quickly. That reality leaves staffing as the most realistic lever, yet revamping how the FAA recruits and trains future controllers will itself take years.
What summer 2024 travelers should expect
With summer storms on the horizon and controller staffing still thin, flyers using Boston—and other Northeast hubs like New York LaGuardia, Newark, and Philadelphia—should anticipate cascading disruptions any time afternoon weather rolls in. Tabarrok forecasts that without intervention, “the costs of delays can double, triple, quadruple over the next 10 years,” resulting in billions more in lost time.
Tips for Travelers
- Book the first flight of the day. Early departures are less exposed to knock-on delays.
- Choose longer connection windows: allow at least 90 minutes domestically and three hours internationally.
- Track incoming aircraft via airline apps; if the plane has not left its previous city, consider rebooking before a cancellation wave begins.
- Sign up for free flight-status text alerts from both the airline and services such as FlightAware.
- When possible, avoid peak-summer afternoons at delay-prone hubs—including Boston, New York, Chicago, and Atlanta—where thunderstorms frequently trigger ground stops.
- Pack snacks and power banks; airport vendors often close late at night when delays drag on.
Questions about Flight delays and schedule padding
Why do airlines pad schedules?
Padding helps carriers hit on-time targets set by the Department of Transportation. If a flight blocked at two hours lands in 2:10, it is listed as late; if the schedule is extended to 2:20, the same flight counts as punctual even though the passenger experience is unchanged.
Is padding illegal?
No. Airlines are free to publish whatever gate-to-gate times they believe are realistic. The practice only becomes an issue when passengers misconstrue padded times as increased punctuality.
Are certain routes worse than others?
Flights in the congested Northeast Corridor routinely appear on the DOT’s list of most delayed services. Still, severe delays can happen anywhere thunderstorms, snowstorms, or staffing shortages create bottlenecks.
Can I get compensated for a delay?
Unlike the European Union, the United States does not have a federal rule mandating cash compensation for delays that are outside an airline’s control. Some carriers offer meal or hotel vouchers on a case-by-case basis; terms are spelled out in each airline’s contract of carriage.
Is relief in sight?
The FAA is expanding training classes for new controllers and investing in next-generation radar and software. However, because certified controllers require years of mentoring, the staffing gap is unlikely to close before the latter half of this decade.
For travelers passing through Boston Logan and other busy U.S. airports, the Harvard study delivers a clear warning: three-hour ordeals that were once rare have become part of the modern flying landscape. Until staffing levels rise or new runways materialize, passengers may need to build extra buffer into itineraries—just as airlines have quietly baked it into their schedules.
