Or let's ask this way: What's the potential next logical system below itass?
From what I remember from the three months I spent in Italy, there's the Strada Statale (~US highways), Strada Regionale (~state highways), and Strada Provinciale (~county highways) (the American equivalents are just me spitballing, not sure if they're accurate). The shields look the same (with SR and SP instead of SS). Now, finding somewhere that lists the Strada Regionale... that doesn't sound fun.
That is correct.
A bit of backstory about this "transfer-back" operation.
In 2001, the right wing government decided for a so-called "devolution" of some central powers (pushed by northern separatists of Lega). For instance, the National Healthcare System was re-arranged into regional subsystems (now under heavy criticism, given the very different approaches to the pandemic and to the vaccine campaign - but that's another story).
Many SS roads were then devolved to regions, which in turn devolved the vast majority of them to the provinces.
In 2014, however, with the pretext of spending review due to the financial crisis, the left wing government basically set provinces' budget to zero. Nominally they still have competencies (over schools, for instance, and of course provincial roads), but no money to finance manintenance, let alone new construction.
Since then, provincial roads fell into a state of profound decay and many denounced this lack of maintenance. ANAS was forced, then, to take some of these roads under its - much larger - budget in order to plan and finance renovations.