Isernia to Viterbo trains might be a good value for money solution: travelling in Italy by train is often rather cheap and faster than taking a bus indeed Trains leave from Isernia and arrive at Viterbo Porta Fiorentina every about 2 hours on average. If travelling with Trenitalia, you need to know the Isernia to Viterbo train schedule: the first train leaves at 09:37, while the last ride is at 17:53. A Isernia to Viterbo train cost about 16.2 €. But how long is the train ride from Isernia to Viterbo? Your journey takes about 5 hours on average.