My driving exprerience
In Italy you take a ticket first at the highway entrance and then pay it on exit. It's possible there is a person in the toll box or cash/debit card terminal. It works pretty well and accepts coins and banknotes without a problem.
I'm not saying It's better to take a plane instead of making a car trip, but be prepared for dramatic weather change when you are down in Italy - once you have the mountains behind you it gets really hot in Italy!