Italian buses are the secret weapon for budget travelers. While everyone books Frecciarossa (€25-50), the same routes cost €5-15 by bus. FlixBus Rome→Naples: €5. Itabus Milan→Rome: €9. The trade-off: slower (1-2 extra hours), less comfortable, but with WiFi, charging ports, and the smug satisfaction of spending €5 instead of €45. Plus: buses serve destinations that trains don't reach — Amalfi Coast villages, mountain towns, Puglia inland.
FlixBus (green buses) — the king. 300+ Italian routes. Rome→Naples €5-12 (3h), Rome→Florence €9-15 (3.5h), Milan→Venice €7-14 (3.5h). WiFi, plugs, toilet. Book on flixbus.it or app. Itabus — Italian competitor, launched 2021. Often cheaper than FlixBus on main routes. Milan→Rome €9-15 (6.5h), Rome→Bari €12-18 (4.5h). Newer buses, more legroom. Book on itabus.it. MarinoBus — southern Italy specialist. Best for: Rome→Lecce, Rome→Calabria, Rome→Sicily. Often the ONLY direct bus to small southern towns. SITA Sud — local Campania buses. The SITA bus along the Amalfi Coast road (Sorrento→Positano→Amalfi) is terrifying and essential (€2.50).
Budget trips: FlixBus/Itabus are 50-80% cheaper than Frecciarossa. South of Naples: Train coverage is sparse below Naples. Buses serve Puglia, Calabria, Basilicata inland far better. Amalfi Coast: No train access — SITA bus is the only public transport. Mountain towns: Buses reach places like Matera, hill towns, ski resorts that trains skip. Night travel: Night buses save a hotel night (Rome→Sicily overnight, €20-30).
Speed: Milan→Rome: 3h Frecciarossa vs 7h bus. Comfort: Trains have more space, bar car, power at every seat. City center to city center: Trains arrive at Termini/Centrale. Buses arrive at Tiburtina/peripheral stations.