A head's up for visitors planning on using either mode of transport during the 2024 high season:
Metro station closures on Line A will affect 2 heavily used stations: Spagna, near the Spanish Steps, and Ottaviano, near the Vatican. The Ottaviano> Battistini section will only be affected from 9:00 PM/21:00 during weekdays. Not sure at what time it'll reopen in the morning but assume it'll be early enough for locals heading to work. Cipro, also near the Vatican, apparently won't be affected before 9:00 PM.
https://www.wantedinrome.com/news/rome-spagna-ottaviano-metro-stations.html
Tram lines closures; appears ALL of them will be affected:
https://www.wantedinrome.com/news/rome-trams-out-of-action-from-may-to-october.html