Events
January
January 4 – The Island Line, Isle of Wight temporarily closes for renovations and Class 483 units are withdrawn from service.[1] The cars originally operated on the London Underground starting in 1938.
January 22 – Opening of the full Beijing–Shenyang high-speed railway.[2]
January 28 – Opening of Porte de Clichy station on Paris Métro Line 14.[3]
February
February 7 – Transport for Wales Rail takes over the Wales & Borders franchise from KeolisAmey Wales.[4]
February 27 – Metrorrey Line 3 commences operation in Monterrey, Mexico.[5]
March
March 4 – Opening of 172 km (107 mi) stretch of North-South Railway.[6]
March 26 – Sohag train collision
April
April 1 – The Moscow Metro Bolshaya Koltsevaya line is extended to Mnyovniki.[7]
April 2 – Hualien train derailment
April 6 – The Te Huia passenger service between Hamilton and Papakuri begins,[8] including the opening of a new transit hub in Hamilton.[9][10]- April 10 – The Île-de-France tramway Line 9 opens.[11]
- April 18 – Toukh train accident
April 24 – Line 3 of the Sofia Metro is extended from Krasno Selo to Gorna Banya- April 25 – Taichung Metro's Green Line commences operation in Taichung.[12] The line had opened the previous November, but was shut down for repairs after trains exhibited faulty couplers.
May
- May 3 – Mexico City Metro overpass collapse
May 6 – Flixtrain begins operating long-distance passenger services from Stockholm to Gothenburg.[13]
May 10 – SNCF open-access operator Ouigo España begins low-cost high-speed rail passenger services over the Madrid–Barcelona high-speed rail line.[14]
May 24 – Kelana Jaya LRT collision
June
June 7 – 2021 Ghotki train collision: The Millat Express from Karachi derails near Daharki in Sindh province and the Sir Syed Express coming in the opposite direction collides with it and overturns, killing at least 50.[15]- June 23 – Renfe begins Avlo low-cost high-speed rail passenger services over the Madrid–Barcelona high-speed rail line.[14]
- June 25
- – Lhasa-Nyingchi Railway, Xiamen Metro Line 3 begins operation.
- – The first phase of Jiaxing Tram begins operation.
- June 26 – Zhengzhou Metro Line 3 Extension begins operation.
June 27 – The Tuen Ma Line fully opens, with a new section between Hung Hom and Kai Tak.[16]- June 28 – Mianyang–Luzhou high-speed railway (Neijiang-Zigong-Luzhou section), Hangzhou Metro Line 8, Hangzhou–Haining intercity railway, Shaoxing Metro Line 1 (Keqiao–Guniangqiao section),[17] Changzhou Metro Line 2, Xuzhou Metro Line 3 begins operation.
- June 29 – Xi'an Metro Line 14 begins operation and merges with the former Airport Intercity Line;[18] Suzhou Rail Transit Line 5 begins operation.[19]
June 30 – Metro Express (Mauritius) extended by 2 stations (Phase 2A).[20]
July
July 5 – Manila LRT Line 2 East Extension opens.[21]- July 20 – 2021 Henan floods overwhelm part of Zhengzhou Metro Line 5, killing 14.[22]
August
August 2 – SRT Dark Red Line of Bangkok suburban railway system begins operation.[23]
August 4 – Milavče train crash
August 6 – The final section of the Delhi Metro Pink Line between Trilokpuri Sanjay Lake and Mayur Vihar Pocket I opens after being previously delayed due to land acquisition and rehabilitation issues.[citation needed]
August 9 – The Tampere light rail system begins operation with Lines 1 and 3.[24][25][26]- August 18 – The initial section of Foshan Nanhai Tram Line 1 opened.[27]
- August 26 – Line 7 and Batong line of Beijing Subway extended to Universal Resort station.[28]
August 28 – Thomson–East Coast MRT line Stage 2 opens.[29]- August 29 – Through operation of Line 1 and Batong line of Beijing Subway started.[30]
August 30 – Opening of the Center City Corridor expansion of LYNX streetcar service in Charlotte, North Carolina.[31]
September
- September 19 – Opening of Line 2 of Harbin Metro.
- September 20 – Opening of the Northern line extension to Battersea[32] in London.
- September 25 – Montana train derailment
October
- October 2 – Opening of the Northgate Link extension in Seattle.[33]
October 25 – Opening of the T3 line of AntRay tram in Antalya between Varsak and Müze stations.[34]- October 25 – Opening of the Odunluk station of Bursaray in Bursa.[35]
October 31 – Salisbury rail crash
November
- November 1 – The Island Line, Isle of Wight recommenced service after upgrades and began using Class 484 units.[36]
November 6 – Opening of Hanoi Metro. The first line 2A (Cat Linh Line) started to operate.[37]- November 18 – Amtrak Cascades service restarts over the Point Defiance Bypass. The rail line was closed in 2017 after the service's inaugural run through the corridor resulted in a derailment.[38]
- November 20 – Regular scheduled passenger services recommence on the Dartmoor Line between Crediton and Okehampton.[39]
- November 21
- – The Mid-Coast Trolley extension of the San Diego Trolley Blue Line opens for service in San Diego, California.[40]
- – The Philippine National Railways' first standard-gauge electric multiple unit stock for the North–South Commuter Railway was delivered.[41]
- November 26 – Harbin Metro Line 3 was extended on both ends to Sports Park on the west and to Taipingqiao on the east.
December
- December 3
– Boten–Vientiane railway opens.[42]- – Yuxi–Mohan railway opens.[43]
- December 7 – 10 stations of the Bolshaya Koltsevaya line of the Moscow Metro, between Mnyovniki and Kakhovskaya, open.[44]
- December 11 – Karlsruhe Stadtbahn city centre tunnel opened.[45]
- December 16 – Kaohsiung begins trial run of the section between Gushan District Office and TRA Museum of Fine Arts stations on the Circular light rail.[46]
- December 17 – São Paulo Metro Line 4 extension to Vila Sônia opens.[47][48]
December 27 – TER Dakar phase 1 opening.- December 28
- – The inaugural section of Kanpur Metro with nine stations opened.[49]
- – Opening of the Nanjing Metro Line S6, and the west extension of Line 2.[50]
- December 29 – Opening of São Paulo Metro Line 15 extension to Jardim Colonial.[51][failed verification]
- December 31 – Opening of Line 11, Line 17, Line 19; extensions of Capital Airport Express, Changping line, Line S1, Line 16; and the central sections of Line 8 and Line 14 of Beijing Subway.[52][53]