Line B
A CAF MB/400 train in Termini Station
Overview
Status	In use
Owner	ATAC
Locale	Rome, Italy
Termini	Rebibbia (north-east), Jonio (north) Laurentina (south-west)
Stations	26
Service
Type	Rapid transit
System	Rome Metro
Operator	ATAC
Daily ridership	156,590 (2023)[1]
History
Opened	9 February 1955; 71 years ago (1955-02-09)
Last extension	21 April 2015
Technical
Line length	18.151 km (11.279 mi) plus B1 branch of 5,5 km[2]
Character	Underground and Elevated
Track gauge	1,435 mm (4 ft 8+1⁄2 in)
Electrification	Overhead lines
Route map Show interactive map Show static map Legend Rebibbia Ponte Mammolo Santa Maria del Soccorso Jonio Pietralata Conca d'Oro Monti Tiburtini FL1 Libia Quintiliani Sant'Agnese Tiburtina FL1 FL2 FL3 - Annibaliano   Bologna 3 19 Policlinico Castro Pretorio 5 14 RM-Giard. FL4 FL5 FL6 Termini A FL7 FL8 LE-FCO Cavour 3 Colosseo C 3 Circo Massimo FL1 FL3 FL5 Piramide 3 RM-Lido Garbatella RM-Lido Basilica San Paolo Marconi RM-Lido EUR Magliana EUR Palasport EUR Fermi 720-CIA Laurentina Show route diagram

Line B is a metro line serving Rome, Italy, and part of the Rome Metro. Despite its name, Line B was the first line to be built in the city. It crosses Rome diagonally from the north-east—starting at the Rebibbia and Jonio branching stations—to the south, terminating at Laurentina in the EUR district. It interchanges with Line A at Termini station and with Line C at Colosseo. The line features 26 stations and is color-coded blue on transit maps.

Overview

The line's first service runs at 05:30 and its last at 23:30, with late-night weekend services extended until 01:30 on Fridays and Saturdays. Line B carries approximately 345,000 passengers and runs 377 trains daily. During peak hours, trains run at a frequency of one every 3 minutes on the shared section and every 4.5 minutes along the branches. Off-peak service frequencies range between 6 and 9 minutes.^[3]

History

The line was planned during the 1930s by the Fascist government to provide a rapid transit connection between the central train station, Termini, and E42, a newly designed district to the south-west. This district was intended as the venue for the Universal Exposition (Expo) scheduled for 1942. However, the exposition was canceled following Italy's entry into World War II in 1940. When construction was halted, several tunnels in the city center (between Termini and Piramide) had already been completed and were subsequently utilized as air-raid shelters.

Construction resumed in 1948, coinciding with the redevelopment of the former Expo site into a commercial and residential area under the name Esposizione Universale Roma (EUR). The line was officially inaugurated on 9 February 1955 by President Luigi Einaudi, with regular public services beginning the following day.^[4]

Following the opening of a new east–west line in 1980 from Anagnina to Ottaviano, that network was designated as Line A, while the original Termini-Laurentina axis was renamed Line B.

In 1990, Line B was modernized and extended from Termini eastward to Rebibbia. On 13 June 2012, a new spur known as B1 opened from Bologna to Conca d'Oro.^[5] This branch was further extended to its current terminus at Jonio on 21 April 2015.

On 16 December 2025, a major connection to the network was established when Line C was extended to Colosseo, turning the station into a key interchange hub.

Extensions

Future extensions have been planned for both branches of the line:

• B1 Branch: Plans exist for an extension beyond Jonio toward the Bufalotta district near the Grande Raccordo Anulare (GRA).^[6]
• Main Line: In early 2026, the city administration approved the official planning document (DOCFAP) to extend the line eastward from Rebibbia. The project includes 6 new planned stations: San Basilio, Torraccia, Casal Monastero, Tecnopolo, Settecamini, and a new terminus at Setteville.^[7]

Rolling stock

Upon its opening in 1955, Line B operated MR100 and MR200 trainsets (collectively known as Automotrice Stanga-TIBB). These were transferred to the Rome–Lido railway in 1987 and replaced by Series MB100 trains to handle growing passenger volumes from the Rebibbia extension.

Since 2010, the network has integrated newer CAF MA300 stock, supplemented since 2014 by MB400 Series trainsets similar to those deployed on Line A.

• 
  Interior of Line B train
• 
  MR200 train at Piramide in 1984
• 
  A side view of the 1990 built MB100 cars at Termini
• 
  CAF S/300 MA300 in service on line B at Garbatella
• 
  CAF S/300 MB400 in service on line B at Piramide

Statistics

Stations

Metro Line B in Rome

2km
1.2miles

26

Rebibbia

25

P.Mammolo

24

S.M.Soccorso

23

Pietralata

22

Monti
Tiburtini

21

Quintiliani

20

Tiburtina

19

Jonio

18

Conca d'Oro

17

Libia

16

Sant'Agnese

15

Bologna (Rome Metro)

14

Policlinico

13

Castro Pretorio

12

Termini

11

Cavour

10

Colosseo

9

Circo Massimo

8

Piramide

7

Garbatella

6

San Paolo

5

Marconi

4

EUR Magliana

3

EUR Palasport

2

EUR Fermi

1

Laurentina

   

Notes

External links

Media related to Line B (Rome metro) at Wikimedia Commons