Complex sentence: The urban service operates with a frequency of about one train every 10 minutes, while the suburban service operates considerably less frequently, with less than a third of the trains making the full two and a half hour journey from Rome to Viterbo.
Split into simpler sentences: The urban service operates with a frequency of about one train every 10 minutes. While the suburban service operates considerably less frequently with less than a third of the trains making the full two and a half hour journey from Rome to Viterbo.