Rolitta,
Not sure where you are staying in Florence, but yes the ZTL's a re a huge issue. When we drove to Florence (and we lived in Rome) we always north of the centro area at a B&B with parking and NOT ANYWHERE close to a ZTL. Rome has a bigger ZTL zone (see: http://tinyurl.com/Rome-ZTL) but the ZTL zones in Florence always seem to be the MOST violated by visitors... so do know your route options BEFORE driving in this area.

The fastest route to Rome is the A1, the toll highway between the cities. Once you're on the autostrada traffic is usually light in early March, but will increase as you near Rome.

The Rome airport is NOT on the way into the city from Florence, but if you don't want to drive in Rome, it is a good dropping-off point for your rental car. As it's a Saturday, many of the in-town rental sites close early. Depending on where you're staying, some hotels - like the Roma Cavalieri - have their own rental car drop-off points (and it's outside the ZTL zones!).

I'd have a GPS for your Tuscany travels - but do know that many units will actually ROUTE your through a ZTL zone so do your homework before getting into the car. You'll also need an IDP if you're coming from the States; it's the law - See: http://tinyurl.com/Italy-IDP

If you're looking for the QUICKEST way to downtown Rome, why even drive? Doesn't sound like you plan on using the car in Rome or stopping along the way? **Take the train** and you'll be there in 90 minutes or less - much faster, (and if you buy ahead) much cheaper than using the car!

Yes do take particular note of the ZTL restrictions. If you do a search of this forum you'll find threads discussing the hefty fines imposed on unsuspecting motorists (my neighbour being one of them).

Bad idea---forget the car in this case and do not drive in Florence or Rome. ^Take day trips by train or bus to Siena and Lucca from Florence and train to Rome. If you must see the hill towns then hire a driver for one day--still less than having a car for several days--plus parking & petrol.

>>>I am going to spend a few days in Florence at the beginning of March and will be renting a car to take one day trips. <<<

Central Florence is ZTL so you can't drive there except to drop off luggage when checking in or out of hotel (not for day trips)and your hotel must arrange notification so your aren't fined. What day trips are you doing? Are you sure you need a car the whole time as you will be paying 30-40€ per night parking?

>>>I am not planning on stopping on any city.<<<

I don't see the point in having a car this day. It's much simpler to take the train (90 minutes). Why pay an extra car rental day and an extra overnight parking fee?

Thank you guys so much for all your replies. The reason why I am renting a car is because my boyfriend travels for business and he gets points through Hertz so the car is FREE so we figure we would take advantage of this. Also, it is the same amount of points to rent a car for 2 days than for a week and that is why we decided to drive it to Rome.

The hotel that we are staying at the first 2 nights in Florence is in via Givanni Agnelli which it seems to be outside of the central Florence and the hotel said that a few blocks away we can park for free. The first day trip will be to: San Gimignano, Siena and Pienza. The second day trip will be to Luca and Pisa.

The last 2 nights in Florence we are staying in Piazza Ognissani which it seems to be central Florence but again the hotel said that there is free parking like 15 minute walk.

In Rome we are staying in a hotel at Viale del Pattinaggio which is a few miles away from Central Rome so I am hoping that we are able to drop off the car as soon as we get to Rome.

So again this is the reason why we are doing all of this by car because its free. I would appreciate any more advice on this now that you guys know the reason behind the car.

Thank you! Thank you!

The car rental may be free but have you seen the price of gas in Italy. In Oct it was $8.50-$9.00 a gallon. I spent $100 in gas in one day.
A car is completely useless in the cities you're visiting and the fines in the ZTL restricted areas are NO joke. If you do incur a fine, the rental company will charge you an additional fee to mail it to you.
Take the bus or train to do your day trips and between cities, enjoy the view and relax.

>>>via Givanni Agnelli<<<

That is way outside the center - nowhere close to the historic center. It's out by the A1. Must be staying at the Sheraton on points. I understand it has very limited shuttle service to the center. Perhaps you can see if there is any public bus if you plan on going into Florence.

>>>San Gimignano, Siena and Pienza. The second day trip will be to Luca and Pisa.<<<

All have ZTL (even tiny Pienza). Learn the ZTL sign and don't cross it. You will need to pay to park at each on the outskirts.

Your second hotel in Florence is inside the ZTL. I would be questioning the hotel about what parking could be available free nearby. Are they expecting you to find a space on the street? If so, good luck with that. You need to learn the street parking signs so you know whether it's a free spot or not. Click the download to see the ZTL map. Your 2nd hotel is in zone A, but zone B is also restricted with cameras at all cross in points.
http://www.serviziallastrada.it/index.php?option=com_remository&Itemid=224&func=startdown&id=150&lang=it

Your Rome hotel is not really in Rome at all. It's in Eur and closer to the airport. I would ditch the car before switching to the 2nd hotel in Florence. I would do all my day trips while staying at the first hotel, ditch the car (at the airport and take the shuttle bus to the center), see Florence while staying at the 2nd hotel. I wouldn't risk the fines in Florence and don't think you will find free parking. If you end up having to pay 40€ per night for parking that would pay your train tickets to Rome. Hertz charges about 40€ (it's in their contract) to provide your info to the police each time you cross a ZTL camera (not just one charge if you cross multiple cameras) plus the fines can be hefty.

When you take the train into Rome, you can switch to the metro (downstairs in the train station) to Eur . You should be able to walk to your hotel from there. If you book your Florence/Rome tickets in advance on Trenitalia, you might snag some of the 9€ tickets for the fast train. The metro will be 1.50€

Here's the metro map. You want Eur Magliana on metro line B.
http://www.atac.roma.it/files/doc.asp?r=4

The center of Florence is pedestrianized and there is no need to take a car there unless that is where your hotel is (in which case you need to get an official pass to bring your car there). Otherwise pick it up outside the area and drop it off in Rome outside the ped zone.