[3] The line is part of Corridor 1 of the European Union's Trans-European high-speed rail network, which connects Berlin and Palermo.

The 254-kilometre (158 mi) railway between Rome and Florence developed from several different lines by several different companies for different purposes and as a result was curvy and slow.

It was expected that the first 138-kilometre (86 mi) section of the line from Roma Termini to Città della Pieve would take five years to complete, but it was not in fact opened until 24 February 1977.

It was a milestone in the history of Italian railways, but progress was subsequently slowed by numerous obstacles, some of a political nature.

The line has a largely straight path with a maximum grade of 0.8%, no level crossings or intersections of any kind with road or rail traffic, and the centre of tracks 4 metres (13 ft) apart to counteract the dynamic effects created by trains passing each other.

Ansaldo STS upgraded the signalling and train protection system with ETCS level 2, and it was first activated on the section between PM Rovezzano - Arezzo South interconnection in December 2020.