Driving in Italy can be very intimidating if you are new to it. Almost all Italian drivers are aggressive drivers and in order to drive more safely you must learn to adapt. It also seems to be the only time Italians are ever in a hurry when doing something. The drivers here remind me of some of the most obnoxious teenage drivers. Imagine a city filled with teenagers all rushing to get somewhere first. When driving in or near Rome you must always expect to be cut off, always expect someone to pull out in front of you, and always expect the driver in front of you to slam on their brakes when stopping or slowing down.
The rules of the road don't seem to matter very much to Italians and are broken all the time; especially by people on mopeds and motorcycles. And to some drivers, red lights are only a suggestion. It seems road lanes don’t mean much either. I often see people driving down the middle of two lanes. If a car wants to pass someone doing this then they flash their lights at the drivers side mirror. This works only when the driver is paying attention of course. At stop lights, sometimes cars will form four lanes where there are officially only two. And when the light turns green, whoever has the fastest car ends up in front.
Merging is a skill in Italy. Often many lanes of traffic will merge into one or there will be several on-ramps and off-ramps crossing over each other, in which case cars are zooming all over in a big free for all. Cars will get inches (sometimes centimeters) away from each other as they all merge into the same lane then separate into opposite directions. It can all be very chaotic but at the same time Italian drivers can be very gracious as well. If a driver has the guts to pull out into on-coming traffic to join a long line of cars then the on coming car will usually slow down to let that driver in. Pedestrians have the right of way here. If a person is on or near a cross walk then cars will usually stop to let the person cross. However, there is a technique to crossing the street. Always make eye contact with the person driving the car and don't hesitate when crossing the street.
Parking is a free for all as well. If the car fits, and it's not blocking a gate, doorway, or the street (too much) then it’s a parking spot. Italians will park anywhere and everywhere so they don't have to pay for parking. That is why having a small car is a must in Italy. There are also very few nice/expensive cars seen on the road in Rome. Just about every car will have dents and scratches from parking in small spaces or getting too close to another car.
Those are a few things to expect when driving in Italy. If you really want to have fun with it then get used to using the horn and study some common Italian hand gestures. You will be just like an Italian in no time!