Helsinki commuter rail (, ) is a commuter rail system serving Greater Helsinki and the surrounding county of Uusimaa. The system is a joint venture between the regional transport authority HSL and national railway operator VR. The system operates on four railway lines and comprises 13 services, all of which terminate at Helsinki Central Station. Within the HSL region, tickets and timetables are fully integrated with other modes of public transport. Four services extend into the operational area of VR commuter rail – tickets issued by VR are needed for journeys further north from Zone D. Both parties discontinued onboard ticket sales in 2017. Commuter rail is a backbone of public transport in Helsinki and is by far the lengthiest rapid transit system in Finland. Carrying a total of around 70 million passengers (2018) a year and operating about 670 departures on each weekday (2019). History Late 1800s The history of local trains in and around Helsinki began on 1 June 1886 with four daily back-and-forth services on the Main Line – two terminated at Malmi station (then a market town in the parish of Helsinge), one at Kerava station and one at Järvenpää station. These services only ran from June to September for their first ten years. Early 1900s The Coastal Line, completed in 1903, was designed and routed with local travel in mind which has since caused issues for operating long-distance trains. Local services on the line were initiated in 1904, with two daily back-and-forth services towards Kirkkonummi station and one towards Karis station. The construction of housing near stations began quickly and by 1910, the number of daily services had increased to ten. 1920s to 1940s During the steam locomotive era, local services were operated with wooden carriages with wide doors for embarkment, attached to locomotives such as the Class Pr1. Passenger numbers increased vastly after Finland gained independence in 1917, with 4 million trips made in 1920 and 9 million in 1924. The Great Depression decreased commuter numbers drastically – at its lowest, only 3 million trips were made per year in the 1930s. At the end of the decade, the tally was recorded at around 4 million. As Finland was forced to lease the Porkkala Naval Base and its surrounding areas to the Soviet Union in 1944, westbound local trains from Helsinki had to terminate at Kauklahti station until the lease period came to an