The one travel data point every site gets wrong

Every flight search result, route page and “how long is the flight to…” snippet leads with the same number: flight time. It’s clean, it’s sortable, and it’s close to useless for deciding how to travel. The number you actually need is door-to-door time: from the moment you lock your front door to the moment you drop your bag at the hotel. Travel sites, ours included, keep putting the smaller number in the biggest font.

The number on the screen is the smallest part of the trip

Take London to Paris. The great-circle distance from Heathrow to Charles de Gaulle, computed from our airport dataset, is about 348 km. Divide by a cruise-ish 800 km/h and you get 26 minutes. That’s the estimate our route page for LHR to CDG will show, labelled as such.

Airline timetables tell a different story. Scheduled flights on this pair run roughly an hour and a quarter to an hour and a half gate to gate at the time of writing, according to schedule aggregator FlightsFrom, with British Airways and Air France operating it. And because Paris is an hour ahead of London, the departure and arrival times on your booking look even further apart than the flight really is.

Then add the bits no flight time includes. Heathrow’s own check-in guidance recommends arriving two hours before a flight to Europe (three for other international flights). You still have to get to Heathrow, and from CDG into Paris. Here’s what that looks like stacked up, against the train that competes with it.

The flight is 26 minutes by our estimate and about 85 by the schedule. The journey is closer to six hours. And Eurostar, which advertises 2 hours 16 minutes and asks London passengers to arrive 45 to 75 minutes before departure, wins comfortably while “losing” on the headline number by nearly an hour.

Even the flight time you’re shown is padded

It gets worse, because the scheduled flight time isn’t a measurement either. It’s a promise engineered to be kept.

A study by Dennis Zhang, Yuval Salant and Jan Van Mieghem, “Where Did the Time Go? On the Increase in Airline Schedule Padding Over 21 Years”, looked at about 43 million US domestic flights on consistent routes between 1997 and 2017. Scheduled durations rose 8.1% on average over that period, and the authors attribute more than 45% of the increase to airlines strategically padding schedules to improve on-time performance. They also found padding rose where competition on a route fell.

This makes sense once you know how on-time is measured. The US Bureau of Transportation Statistics counts a flight as on time if it arrives at the gate less than 15 minutes after its scheduled time. Stretch the schedule and more flights are “on time” without flying any faster. It’s not sinister. It’s what any organisation does when it’s graded on a number it also sets. But it means scheduled block time is a planning buffer, not a travel time.

The four-hour promise nobody’s keeping

Europe has actually tried to plan around door-to-door time. The EU’s Flightpath 2050 vision set a goal that 90% of travellers within Europe should be able to complete their journey door to door within four hours.

When researchers at the German Aerospace Center (DLR) tested that goal against real flight schedules and passenger demand, the numbers weren’t close. In their 2019 analysis, adding just 30 minutes of airport access and processing time before departure and 15 minutes after arrival to the shortest real flight times meant only 82.4% of passengers could make it in four hours. Under more realistic but still plausible assumptions, 45 to 60 minutes at each end, the share fell below half. And they found around 12% of travellers fly on city pairs that are simply too far for four hours regardless.

Notice what that means. Even the researchers modelling the target use airport buffers far shorter than Heathrow’s own two-hour recommendation. Real door-to-door times are longer than the optimistic model, which is already failing the goal.

How we handle it on TravellerSeed

We’re part of the problem, so here’s how we try not to make it worse.

Our route data comes from OpenFlights, a historical snapshot. It gives us airports and routes, but not live schedules. So our route pages show an estimated flight time: great-circle distance divided by 800 km/h, and we label it as an estimate. It’s useful for one thing: comparing routes against each other. Lagos to London (about 5,000 km on our dataset) versus Lagos to Paris, say. It is not a schedule and it will always be shorter than one, because it ignores taxiing, holding, routing around airspace and padding.

What we try to do around that number:

• Say what it is. “Estimate” is on the label, not in a footnote.
• Put the airports in view. Every route page links to both airport pages, because how far the airport is from where you’re actually going is half of door-to-door time.
• Show time zones at both ends, since a one-hour offset (London to Paris) or a six-hour one makes the booking times look nothing like the travel time.
• Not pretend to be a timetable. For actual departure times, check the airline.

What you should do instead

When you’re comparing ways to get somewhere, build the door-to-door number yourself. It takes two minutes:

1. Home to departure point. Use a maps app at the real time of day you’d travel, not at midnight.
2. The buffer the operator asks for. Take it from the airport’s or airline’s own site (Heathrow says two hours for Europe, three for other international), or the rail operator’s arrival guidance.
3. The scheduled time, not the distance estimate. Look up the actual timetable on the airline’s site or a flight search engine.
4. Exit time. Bags, immigration, and a walk to the train or taxi rank. Longer for long-haul and non-Schengen arrivals.
5. Arrival point to your actual destination. Check how far the airport really is from the city; our airport pages help here.

Then compare totals, not flight times. On short trips, the train, a different airport or an earlier departure often wins by an hour. On long-haul, where the flight dominates, the extra time at each end is still worth knowing when you plan meetings, check-in times or a pickup.

Flight time is the number that’s easy to show. Door-to-door time is the one you’ll live through. It’s worth the two minutes.