The right mode of transport saves you $30–100 per leg in Europe. Make the wrong call repeatedly and your transport budget doubles. Here's the decision framework.
When to Take the Bus (Flixbus / RegioJet)
Buses win when: the journey is under 6 hours, rail connections are slow or require multiple changes, or you're travelling in Western Europe where trains are expensive.
Flixbus covers 40+ countries and can be extraordinarily cheap if you book early — London to Amsterdam for $8, Paris to Barcelona for $15. These prices disappear fast; book 4–6 weeks ahead. The app is good, the buses are clean, WiFi is reliable.
RegioJet operates in Central and Eastern Europe (Czech Republic, Slovakia, Hungary, Poland, Austria) with free coffee on board and better seats than Flixbus. Often cheaper than trains on the same route.
When to Take the Train
Trains beat buses when: the journey is over 6 hours and the train is overnight (saving a night's accommodation), the scenery is spectacular and worth seeing, or rail passes give you a better per-journey price.
Night trains are undergoing a European renaissance. The European Sleeper (Brussels to Vienna) and Nightjet network have expanded dramatically. A couchette on an overnight train costs $30–50 and replaces both a bed and a transport ticket.
Rail passes (Interrail for EU residents, Eurail for non-EU) make economic sense only if you're travelling fast and covering a lot of ground — 3+ countries in 10 days. For slow travel, point-to-point tickets almost always win on price.
When to Take a Budget Flight
Fly when: the destination is over 6 hours by ground transport, or budget airlines offer genuinely cheap fares that undercut the train.
Calculate total cost honestly: budget airline price + getting to/from low-cost airport (often 45–90 minutes outside the city) + luggage fees + time. A $20 Ryanair flight that costs $30 in airport transport and 3 hours of your time is often worse value than a $40 train.
Marshrutkas: The Secret Weapon
In Eastern Europe and the Caucasus, marshrutkas (shared minibuses) are the default cheap transport. They depart when full rather than on a schedule, cost $1–5 for most journeys, and go everywhere buses don't. Ask at your hostel where the marshrutka stand is for your destination — it's rarely at the main bus station.