There are always strikes in Rome. I would say at least once a month maybe more. The link above is a good source to find out when they are happening. Also if you are new to Rome and need to get to the other side of the city, on their site you can enter START point and FINISH point and the site will tell you what combination (if any) of buses, train & trams you need to catch to arrive at your destination as well as giving you a time frame.
Rome’s subway system can come in handy when you’re traveling to these locations (look for the big red M at the entrance to each station) and a one-way ticket costs €1.50 which you can use on trams, and buses unlimited for 90 minutes and 1 ride on the metro. There are also tourist tickets called BIT or CIS good for unlimited rides. BIT “Biglietto Turistico Integrato” is a 3-day ticket, valid until midnight of the third day on which the ticket is validated, the CIS “Carta Integrata Settimanale” is a weekly one.
Both BIT and CIS grant you unlimited rides on Atac or Cotral buses, subways, and some local trains. Tickets can be sold by tabacchi (tobacconists), which are housed in buildings with bold black T’s on white or dark blue signs.
There is also a ticket called “Roma Pass” that offers you transport and two museums free of charge as well as reductions for all other museums and major events in Rome for a 3-day pass. The “Roma Pass” is available in all museums and the Tourist Information Points.