It depends on the day of the week Ferragosto lands on. This year, 2016, it landed on a Monday so everyone made it a 3-day weekend and took off on Saturday the 13th. The trains were packed and traffic was at a standstill that day, and on the 15th the trains and roads were empty because everyone had already left.

I wouldn't change my flight to stay in Rome to "see" Ferragosto. I also wouldn't decide how to get to the airport 9 months ahead of time. In 2017 Ferragosto is on a Tuesday. When you get to Rome or a few weeks before hand, get a sense of things. Your hotel can help with that. I suspect that most people will take Monday the 14th off, and make it a long weekend by leaving on Saturday the 12th, and traffic won't be too outrageous on the 15th.

However, if the exodus hasn't already happened, and 3 million romans are leaving on the 15th, the trains will be crowded, but taking a taxi will be worse. Trains don't sit in ten mile long traffic jams like cabs will.

My suspicion is that most people are going to leave on Saturday the 12th, and the trains and highways will be reasonably moveable on the 15th.

I think there are too many unknowns to tell you what to do 8 months before. As Ferragosto approaches, more information will come out. Just don't change your flights for it. Do be attentive about how you are going to get to the airport. You do not want to be in a car during the height of Ferragosto traffic whether it's the 12th or the 15th. It's better to sweat it out on a train for 40 minutes than to be bumper to bumper traffic for hours.

I would never recommend missing a last night in Rome, but if the day of your flight out is the day when the exodus takes place, train is better than taxi, and staying at the Hilton at the airport the night before might be best. http://www.italymagazine.com/italy/t...ays-ferragosto