Speed cameras Italy

No but they still operate effectively, and you can't tell which are active and which are defunct day or night (unless some public-spirited criminal has vandalized it). (Edited to remove ambiguity)

Good to know, thank you

e6,

The cameras may not "flash" during dark hours, but that doesn't mean they're not able to capture license plate information. Have a look at this website - http://www.autostradetech.it/en/solutions/security-access-control/tutor-system.html , which states that the device is capable of "Continuous measurements, 24 hours a day, 365 days a year". If the traffic control device is mounted on a bridge over a motorway which has good LED street lighting on either side of the bridge, that might be sufficient to allow a photo capture.

They are posted on viamichelin motorway routes, but the best policy is to obey the speed limits.

There are many “fixed” speed cameras (known in Italy as “autovelox” cameras from the brand name of the original devices). They can operate at night.
They are enclosed in boxes like this, although they are not all alike (some are orange, some are blue, etc.)
Many are inactive, and actually there is no longer an apparatus inside, but nobody knows which, therefore it is safe to slow down before all.
There are also mobile cameras on patrol cars or temporarily set up by a patrol.
There are however navigation apps that can warn you of their presence.
The most used by Italians is Waze, but there are others.
I generally use Waze when in Italy.
Google Maps (Google owns Waze) started the same warning system in 2019, but I haven’t tested it yet in Italy.