I just want to warn visitors to Firenze that if you travel on the bus, you MUST VALIDATE your ticket before you sit down. All you do is look for the arrow on your ticket, stick the end with the arrow into the machine, listen for the click, and pull the ticket out. SAVE IT because the "ticket police" might come around and ask you to show your ticket. We witnessed several travelers who didn't know about validating their tickets get fined. I wish Rick had VALIDATE YOUR BUS TICKET emblazoned on the cover of his Italy guidebooks!
Barbara,
Thanks for the reminder ;-)
You must also validate Regionale train tickets (except those purchased online-- which are already pre-validated)
Enjoy Italy!
Barbara, validating public transit tickets, passes (the first time you use them) and regionale train tickets is pretty much required throughout Italy and in other part of Europe as well. How that's done varies per type of transit but validation is proof that you're not trying to re-use a ticket. It's been a hot topic of discussion on the forums, and covered in RS articles. A couple of examples:
https://www.ricksteves.com/travel-tips/transportation/city-transit/buses
https://www.ricksteves.com/travel-tips/transportation/city-transit/riding-europes-subways