M4 (Istanbul Metro)
The M4, officially referred to as the M4 Kadıköy - Sabiha Gökçen Airport metro line, is a, 23-station rapid transit line of the Istanbul Metro. It is colored deep pink on the maps and route signs. Running between Kadıköy and Sabiha Gökçen Airport, it is the first rapid transit line operating on the Asian side of Istanbul. The M4 mostly runs under State road D100, parallel to the Istanbul-Ankara railway and is entirely underground.
History
A plan to build a subway line on the Asian side of İstanbul was approved in 2005. In 2008, a 751 million construction contract was awarded to a consortium of Astaldi, Makyol and Gülermak. The rolling stock was ordered from the Spanish company CAF. In mid-2010, the construction of the tunnels was completed and the track laying started. The route has connections with TCDD's Marmaray system at Ayrılıkçeşmesi and the Istanbul Metrobus system at Ünalan. The scheduled opening date was December 2011 up to Kartal, but it was postponed because of signalization works.The M4 opened on 17 August 2012 with a large ceremony in Kadıköy, attended by Prime Minister Recep Tayyip Erdoğan. On 29 October 2013, with the opening of Marmaray rail service under the Bosphorus, Ayrılık Çeşmesi station was opened to allow passengers to transfer between lines. On 10 October 2016, 3 new stations were added to the line. On 2 October 2022, 4 new station were added to the line. Thus, the length of the line reached 33.5 km.
The addition of 100 new vehicles to the Kadıköy-Sabiha Gökçen Airport metro line fleet is undertaken by Bozankaya.
Stations
The M4 has a total of 23 stations in operation, with 6 more under construction.| Station | District | Opened | Connections |
| Kadıköy | Kadıköy | 17 August 2012 | Şehir Hatları İDO Turyol İETT Bus: 1, 3, 3A, 3B, 8, 8A, 11D, 12A, 12H, 13, 13B, 13Y, 14, 14A, 14C, 14D, 14DK, 14E, 14F, 14K, 14KS, 14M, 14R, 14S, 14ŞB, 14Y, 15BK, 15F, 15TK, 16, 16D, 16K, 16KH, 16Y, 17, 17L, 18K, 19, 19EK, 19F, 19S, 21A, 21C, 21G, 21K, 21U, 110, 120M, 125, 130Ş, 222, 319, 500A, 500T Havabüs |
| Ayrılık Çeşmesi | Kadıköy | 29 October 2013 | TCDD Transport: Marmaray |
| Acıbadem | Kadıköy | 17 August 2012 | İETT Bus: 3A, 11T, 13M, 13Y, 14A, 14BK, 14DK, 15BK, 16A, 16B, 16C, 16F, 16KH, 16M, 16U, 16Y, 16Z, 17K, 18E, 18K, 18Y, 18Ü, 19, 19A, 19B, 19E, 19FK, 19H, 19T, 19Z, 20E, 20Ü, 21B, 21C, 21G, 21K, 21U, 130, 130A, 130Ş, 319, 320A, E-10, E-11 |
| Ünalan | Kadıköy | 17 August 2012 | Metrobus: 34A, 34AS, 34G, 34Z İETT Bus: 3A, 11T, 130, 13M, 13Y, 14A, 14BK, 14DK, 15BK, 16A, 16, B, 16C, 16F, 16KH, 16M, 16S, 16U, 16Y, 16Z, 17K, 17P, 18A, 18E, 18K, 18M, 18Ü, 18V, 18Y, 19, 19A, 19B, 19E, 19FK, 19H, 19T, 19Z, 20E, 20Ü, 21B, 21C, 21G, 21K, 21U, 130A, 130Ş, 319, 320A, E-10, E-11 Havabüs |
| Göztepe | Kadıköy | 17 August 2012 | İETT Bus: 3A, 8E, 9K, 10E, 10G, 11T, 13M, 13Y, 14A, 14B, 14BK, 14ES, 15BK, 15ÇK, 15SK, 16A, 16B, 16C, 16F, 16KH, 16M, 16S, 16U, 16Y, 16Z, 17K, 17P, 18A, 18E, 18K, 18M, 18Ü, 18V, 18Y, 19, 19A, 19B, 19E, 19FK, 19H, 19T, 19Z, 20D, 20E, 20K, 20Ü, 21B, 21C, 21G, 21K, 21U, 129T, 130, 130A, 130Ş, 202, 251, 252, 319, 320A, E-10, E-11 |
| Yenisahra | Kadıköy | 17 August 2012 | Istanbul Metro: İETT Bus: 8A, 8Y Havabüs |
| Kozyatağı | Kadıköy | 17 August 2012 | Istanbul Metro: İETT Bus: 14KS, 14T, 15KB, 16A, 16B, 16C, 16F, 16FK, 16KH, 16S, 16U, 16Y, 16Z, 17K, 17P, 19, 19B, 19FK, 19H, 19Z, 21B, 21C, 21G, 21K, 21U, 129L, 129T, 130, 130A, 130Ş, 251, 252, 319, 500T, E-10 |
| Bostancı | Kadıköy | 17 August 2012 | İETT Bus: 10, 13AB, 14KS, 14T, 15KB, 16A, 16B, 16C, 16F, 16KH, 16S, 16U, 16Y, 16Z, 17K, 17P, 19, 19B, 19D, 19FK, 19H, 19SB, 19Z, 21B, 21C, 21G, 21K, 21U, 129L, 130, 130A, 130Ş, 251, 319, 500T, E-10 |
| Küçükyalı | Maltepe | 17 August 2012 | İETT Bus: 16A, 16B, 16C, 16KH, 16S, 16U, 16Y, 16Z, 17K, 17P, 19B, 19H, 19Z, 21C, 21G, 21K, 21U, 130, 130A, 130Ş, 251, 500T, KM41, KM45 |
| Maltepe | Maltepe | 17 August 2012 | İETT Bus: 16A, 16B, 16C, 16KH, 16S, 16U, 16Y, 16Z, 17K, 17P, 21C, 21G, 21K, 21U, 130, 130A, 130Ş, 133N, 251, 500T, E-10, KM42, KM43, KM44 |
| Huzurevi | Maltepe | 17 August 2012 | İETT Bus: 16B, 16C, 16KH, 16S, 16U, 16Y, 16Z, 17K, 17P, 21C, 21G, 21K, 21U, 130, 130A, 130Ş, 133N, 136, 136R, 136Z, 251, 500T, E-10 |
| Gülsuyu | Maltepe | 17 August 2012 | İETT Bus: 16B, 16C, 16KH, 16S, 16U, 16Y, 16Z, 17K, 17P, 21K, 21U, 130, 130A, 130Ş, 133N, 251, 500T, E-10 |
| Esenkent | Maltepe | 17 August 2012 | İETT Bus: 16B, 16C, 16KH, 16S, 16U, 16Y, 16Z, 17K, 17P, 21K, 21U, 130, 130A, 130Ş, 500T, E-10, KM30, KM33 |
| Hastane -Adliye | Kartal | 17 August 2012 | İETT Bus: 16C, 16KH, 16S, 16U, 16Z, 17K, 17P, 21K, 17S, 21K, 21U, 130, 130A, 130E, 130Ş, 132G, 134YK, 251, 500T, E-10, KM11, KM21, KM23, KM25, KM29, KM32, KM60, KM70, KM71 |
| Soğanlık | Kartal | 17 August 2012 | İETT Bus: 16C, 16KH, 16S, 16Z, 17K, 17P, 21K, 130, 130A, 130E, 130Ş, 132G, 132M, 134GK, 251, 500T, E-10, KM11, KM12, KM21, KM23, KM25, KM29, KM32, KM60, KM70, KM71 |
| Kartal | Kartal | 17 August 2012 | İETT Bus: 16C, 16KH, 16S, 16Z, 17K, 17P, 21K, 130, 130A, 130E, 130Ş, 131K, 131V, 131Y, 132C, 132ÇK, 132G, 132M, 132N, 132S, 132T, 132Y, 132Z, 134, 134CK, 134GK, 134K, 134UK, 251, 500T, E-10, KM11, KM12, KM21, KM23, KM25, KM29, KM31, KM32, KM60, KM70, KM71 |
| Yakacık -Adnan Kahveci | Kartal | 10 October 2016 | İETT Bus: 16C, 16KH, 16Z, 17K, 17P, 130, 130A, 130E, 130Ş, 132G, 132Ş, 132T, 251, 500T, E-10, KM11, KM12, KM23, KM25, KM29 |
| Pendik | Pendik | 10 October 2016 | İETT Bus: 16C, 16KH, 16Z, 17K, 17P, 130, 130A, 130E, 130G, 130Ş, 132, 132A, 132B, 132D, 132E, 132H, 132K, 132P, 132G, 133GP, 132T, 132Y, 251, 500T, E-9, E-10, KM10, KM11, KM12, KM13, KM23, KM24, KM25, KM28, KM29 |
| Tavşantepe | Pendik | 10 October 2016 | İETT Bus: 16KH, 17K, 17P, 130, 130A, 130E, 130Ş, 132F, 132T, 132Y, 500T, E-9, KM2, KM10, KM11, KM12, KM13, KM14, KM23, KM24, KM29 |
| Fevzi Çakmak–Hastane | Pendik | 2 October 2022 | İETT Bus: 16KH, 132P, 132V, 132Y, KM29 |
| Yayalar–Şeyhli | Pendik | 2 October 2022 | İETT Bus: 16KH, 132, 132A, 132B, 132D, 132E, 132H, 133GP, 133Ü, E-10, KM18, KM25, KM27, KM28, KM29 |
| Kurtköy | Pendik | 2 October 2022 | İETT Bus: 16KH, 132, 132A, 132B, 132D, 132E, 132H, 133GP, 133Ü, E-10, KM18, KM25, KM27, KM28, KM29, KM37 |
| Sabiha Gökçen Havalimanı | Pendik | 2 October 2022 | TCDD Taşımacılık: Yüksek Hızlı Tren İETT Bus: E-3, E-9, E-10, E-11 Havabüs SG-1, SG-2 |
Specifications
The stations Kadıköy, Ayrılıkçeşmesi, Ünalan and Göztepe are situated below sea level. The average distance between the stations is. The distance between the stations at Maltepe and Huzurevi is the shortest at. The distance between Bostancı and Küçükyalı is the longest with. The Operation Control Center of the line is situated in Esenkent and the depot is located in Maltepe. Another depot is to be built in Kaynarca when the line extends there.Train frequency is currently every 5 minutes during peak hours and technically could be shortened to 90 seconds. Trains remain at stations for an average of 15 seconds. Four-car trains have a 1,309 passenger capacity and eight-car trains have 2,618 capacity. Ridership capacity in one direction is 70,000 passengers hourly. Total travel time of the entire line is around 52 minutes.