advice for airport travel

If it were me I'd schedule a taxi.

Best way is a taxi.

Petticoat, Roma passes will not work for transport to Fiumicino, and there are no trams that I know of that go to the airport either.

A taxi is probably be your BEST solution that early in the morning (and well worth the price for that hour, and which is not a "fortune" for two people) but it might help to know exactly where in Trastevere you'll be staying,

I have used Rome Cabs for meeting my flights and they are recommended by many on this forum. Book through their website http://www.romecabs.com or Phone 339 – 352 5028. Current costs at 5 am are $60 for up to three people in a cab. Well worth it, I think.

Best to book a few days in advance rather than call just before you need them. Safe journey home.

There are trains from the airport to the Trastevere train station and back, but I don’t believe they go that early. You could check, but if I were you I’d spring for a taxi. It’s a fixed rate and not all that expensive for two people. Much better than missing a flight because you tried something you weren't certain of. If you do decide on a taxi it is best to call or have someone who speaks Italian call for you to prearrange it, as flagging down a taxi on the street is iffy and not usually possible.

I checked. Looks like the earliest trains to the airport from both Trastevere and the Termini stations don’t start running until after 5 am. I wouldn’t risk it for an 8 am flight. I would either take a cab or stay at an airport hotel.

Taxi rates from Rome to the airport are fixed. So, you pay a flat rate. It used to be about 50€. Your best option is to have the hotel desk clerk call up a cab for you or walk to a taxi stand if one is close by. I would just pay for a taxi rather than stress over this. Getting to the airport is important.

Is it a direct flight back to the US? I am guessing it is a connecting flight to somewhere else in Europe for the return. 8am is little too early for direct flights. Therefore, getting there by six should be fine since it is probably a domestic flight. That means you can take the 5am train if you do not want to take a taxi.

Yes, we have a layover in London.
Right now we are staying in Trastevere on the corner of Via Danodola and Via Glorioso.

My advice is to schedule a taxi. We just did this a week ago from Paris home to Denver. Pre booked (night before) taxi arrived at our hotel right on time, no traffic to CDG that early (4AM) and we arrived in plenty of time to do whatever needed to be done before relaxing at our gate with a cup of cafe au lait and one final croissant. I am an anxious flier so knowing there would be a reliable transport to the airport helped me sleep some the night before and made my flight day just a little easier.

Take a taxi. Why take a taxi to the station than a train? Not much savings in the end anyhow.
From Trastevere at that time in the morning the taxi will get you to the airport in 25 min.

For many years we've used romashuttle.com at about the same cost as a taxi. The taxi is another good idea with their fixed rates. If it were me, and considering the overall cost of the trip, spending 48€ or 50€ would not be a fortune.

Buon viaggio,

Thank you everyone for sharing thoughtful advice and experience. I am taking the travel by taxi. This will be my second taxi ride ever. I am paying for peace of mind I think right now. Thank you to all!