A while back I posted about this inscription on the arch on the south end of the 19th century Piazza della Repubblica.  I’ve just come across additional info and wanted to update:

The inscription reads “L’antico centro della città da secolare squallore a nuova vita restituito,”

Translated to English says: “The old center of the city restored to new life after centuries of squalor.”

Isodoro del Lungo, a city councilor, wrote the inscription especially for the Arcone.