Line S4 (Milan suburban railway service)

Camnago Lentate–Milano Cadorna
An S4 train at Milan Affori.
Overview
StatusOperational
LocaleMilan, Italy
Termini
Stations13
WebsiteTrenord
Service
TypeCommuter rail
SystemMilan suburban railway service
Route numberS4
Operator(s)Trenord
History
Opened2004
Technical
Line length23 km (14 mi)
Track gauge1,435 mm (4 ft 8+12 in)
Electrification3,000 V DC
Route map

The S4 is a commuter rail route forming part of the Milan suburban railway service (Italian: Servizio ferroviario suburbano di Milano), which converges on the city of Milan, Italy.

The route runs over the infrastructure of the Milan–Asso railway. Like all other Milan suburban railway service routes, it is operated by Trenord.