 The increasing traffic has made it necessary to double the track, beginning in 1975.The doubling of the Montesanto-Bagnoli (8.5 km) and Arco Felice-Torregaveta (5.9 km) sections have been completed and work on the remaining section (Bagnoli-Arco Felice (5.7 km)) is well under way.Trains travel every 20 minutes.