We are arriving in Rome at 6:50am in mid September and want to take a train immediately to Florence. I'm worried about making a reservation for a train for the two of us and then missing it. I'm thinking that perhaps I will buy a train ticket once we arrive at Termini but I don't want to spend an hour in a lineup or find that we can't get on any trains because they are full. Am I worrying for nothing?

Reservations on trains are generally recommended but not required. I would always get a reservation when possible so that I am guaranteed of having a seat on the train. If you don't have a reservation, you can get onto a full train, but risk standing for the whole trip. Have you tried booking your train tickets online with Trenitalia (http://www.trenitalia.com)? I believe that if you have a full fare ticket, if you miss the train, you can get onto the next train without any surcharge or penalty.

If you are arriving in Rome, presumably FCO? then buy the tickets to Firenze at FCO ticket booth, NOT TERMINI, since you need to buy Leonardo Express tickets to Roma Termini anyway.

Large stations tend have longer lines.

If you have a full price ticket, you can change the reservation before the departure and I believe up to one hour after the departure.

What I did using a recommendation I got here, was to use Trenitalia to buy full price ticket using ticketless option for the train that I would never miss. Once I arrived, I changed the reservation at FCO for an earlier train, at no cost. If there was no seat on earlier train, there was at least a train that day that I was guaranteed a seat. I used this method because it was just before the Easter.

When we were in Europe, we only reserved and bought our tickets in advance for the overnight train. We took two other train rides in Italy, one from Venice to Florence, and then later from Florence to Rome, and had no trouble getting on the next train out of the city. It'd be good to have the schedules just so you don't wait around long, but other than that it shouldn't be hard to get on another train to Florence. I think they run every hour or so.

Happy travels,

Jules

Thank you everyone - that helps alot! Ciao