We are traveling to Rome May 5th and normally would just stand in taxi line but with the Pope dying and jubilee I am wondering if we should pre book taxi or ride from the rome airport to Trevi area where we are staying?
It’s not necessary.
There is an official taxi line as you exit the terminal. You just line up; it typically doesn’t take too long.
Not necessary
Recent thread with more info
https://community.ricksteves.com/travel-forum/italy/taxi-or-private-transfer
Another option depending upon where you are staying, your hotel may be happy to send a "car" for the same money.
I believe that the most economical way is to prebook an airport transfer from one of the well-regarded companies like:
ROME SHUTTLE LIMOUSINE
Driver will meet you inside the terminal with your name on a sign; their price is 55 euro for two from FCO, with luggage included.
In my experience, hotels charge more than the usual taxi fare for the transfer
The taxi fare is 55€ (flat rate imposed by the City of Rome). It’s all inclusive (no extra charge for luggage, etc. (make sure the taxi driver doesn’t try to play smart). The queue at the taxi stand has never taken too long in my experience, as there are dozens of taxicabs waiting.
You can prebook a limo car type of service, which will wait for you at the arrival hall with a big sign with your name. They generally cost a bit more than the official taxi service, but you can look for one online and decide what works best for you.