To get to Trastevere Roma station from Fiumicino airport, is it better to take the Express to Termini then transfer to another train to Trastevere, or is it better to take the FRI train from Fiumicino to Trastevere Roma station? Thanks!
Take the FR1 and a cab from there if it is not walking distance. Much quicker and less stressful. You would have a big hike in Termini to get from the L Express to the train/ssubway.
I think the answer to your question depends on the locale of your accommodation in the Trastevere neighborhood. Where is it located? Closer to Roma Trastevere or closer to the Mastal metro station. If you are simply asking the easiest rte take the FM1 from FCO to Trastevere Roma. Have you checked the Ron in Rome website? Informational and pratical!!