The Honest Framework
Travel writers typically have a train bias — trains are more pleasant, more sustainable, better for the journey as an experience. That's all true, and it still doesn't mean the train is always the right answer. The right tool depends on the specific journey: the distance, the time value, the price difference, and whether the journey itself matters. Here's how to actually decide.
When the Train Wins
City-centre to city-centre, under 3 hours. The train beats the plane on total journey time for any city pair where the train journey is under 3 hours — once you add check-in (45–60 minutes minimum), the drive or transit to a budget airport (often 45–90 minutes outside the city), and the equivalent at the other end, a 2.5-hour train journey typically involves less total door-to-door time than an 80-minute flight.
The benchmark city pairs where this logic is most clear: London–Paris (2h15 by Eurostar), Paris–Amsterdam (3h17 by Thalys), Madrid–Barcelona (2h30 by AVE), Milan–Rome (3h by Frecciarossa), Paris–Lyon (2h by TGV), Brussels–Amsterdam (2h by Thalys). On all of these, the train competes with or beats flying on total journey time, is significantly more comfortable, and drops you in the city centre rather than 40km outside it.
When the journey is the point. The Bernina Express through the Swiss Alps, the overnight Caledonian Sleeper from London to the Scottish Highlands, the coastal train from Bergen to Flåm — these are experiences that a flight replaces with a commute. If the train journey between two destinations is listed as one of Europe's great train journeys, take the train. You're not choosing a mode of transport; you're choosing an experience.
Night trains for overnight journeys. European night trains are experiencing a revival: the Nightjet network (Austria/Germany/Switzerland), the EuroNight services, and new routes opening regularly. An overnight train from Paris to Vienna or Vienna to Rome saves a hotel night, deposits you in the city centre at a reasonable hour, and provides a more comfortable sleep than most budget airline seats. Book in advance — couchette and private cabin reservations sell out.
When the Plane Wins
Long distances, especially in southern and eastern Europe. Budapest to Lisbon is 2,500km. The train is a 30-hour journey requiring at least one connection; the flight is 3 hours from €30–80 on Wizz Air, Ryanair, or similar. The price and time calculation doesn't even require deliberation. Apply the same logic to any journey where the train would take 8+ hours: unless the journey itself is the destination (overnight train), the plane wins on time and often on price.
When budget airline prices are genuinely low. A €20 Ryanair fare from London Stansted to Porto, all-in, is cheaper than the Eurostar to Paris alone. These fares exist, they're not always available, and when they are, the environmental case for not flying is real but the economic and time case is hard to argue with. Factor in the total door-to-door time and the full cost including bags and transfers.
When the Bus Wins
The bus wins on price, primarily. FlixBus connects most European cities for €10–40 — consistently cheaper than rail, usually slower, often surprisingly comfortable on modern coaches with WiFi and power sockets. The routes where it's most competitive: Central and Eastern European city pairs (Budapest–Prague, Warsaw–Berlin, Vienna–Kraków) where rail prices are higher and the bus journey is only modestly longer. For overnight journeys on routes where night trains don't operate, the bus is the budget-conscious default.
The bus also wins for flexibility: FlixBus tickets are cheap to change (or change for free on some fares), while advance train fares in many European countries are non-refundable and non-changeable.
A Practical Decision Framework
- Is the city-centre to city-centre train journey under 3 hours? → Take the train.
- Is the journey a "great train journey" (Alps, fjords, coastal routes)? → Take the train.
- Is an overnight train available for a 6–10 hour journey? → Consider the overnight train seriously.
- Is the budget flight fare (total, including bags and transfer) under €50 for a long journey? → Consider flying.
- Is the total journey over 6 hours by train and a flight exists for under €80? → The plane probably wins on time.
- Is the budget tight and the journey 3–8 hours? → Check FlixBus.