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While Mumbai Metro-3 is set for an inauguration soon, the under-construction Mumbai Metro 4 or Wadala-Thane Ghodbunder green line is set to be longest elevated line in the network

Mumbai Metro Interchanges: Mumbai has four functional Metro lines at the moment. (File)
Mumbai is in the middle of an engineering marvel, with a Metro puzzle unfolding and changing the way the city travels. Underground, overground or elevated, a mix of both, the city will get a Metro line of each kind, once the full network is in place.
Mumbai Metro-3 is set for an inauguration soon. As of now, which is the longest elevated Mumbai Metro line? What is the route? Is it ready?
Which is the longest elevated Mumbai Metro?
Mumbai Metro 4 or the green line is set to be the longest elevated line in the network. It will also have an extension of 4A, which is increase its length further.
📍 #ठाणे |ठाणेकरांचे मेट्रोचे स्वप्न साकार..!
वडाळा ते गायमुख दरम्यान तयार होत असलेल्या मेट्रो – ४ तसेच गायमुख ते विजय गार्डन या मेट्रो – ४ अ मार्गावरील मेट्रोची ट्रायल रन आज घेण्यात आली. मुख्यमंत्री देवेंद्र फडणवीस यांच्यासह या मार्गावर प्रवास करून ही ट्रायल रन यशस्वीपणे… pic.twitter.com/ramK5oceT6
— Eknath Shinde – एकनाथ शिंदे (@mieknathshinde) September 22, 2025
Mumbai Metro 4 & A: All about the lines
The under-construction Mumbai Metro-4 is the 32.32-km elevated line along the Wadala-Ghatkopar-Mulund-Thane-Kasarvadavali route. It will have 32 stations and connect eastern suburbs of Mumbai with key parts of Thane.
The Mumbai Metro-4A will be the 2.66-km elevated extension between Kasarvadavali and Gaimukh. It will take Line 4 into Ghodbunder Road, covering Gaimukh. The extension is under construction.
EXPLAINED | Mumbai Metro 4, 4A: Ride High From Wadala To Thane, Minus The Traffic At EEH, LBS & Ghodbunder
The lines will reduce road traffic along the Eastern Express Highway and LBS Road, decongest Central and Harbour line trains.
It will provide interconnectivity with other Metro lines at:
Line 2B (at Ghatkopar)
Line 5 (at Kapurbawdi)
Line 6 (at Kanjurmarg)
Phase one is expected to be operational by 2026 and the full corridor by 2027.
How does Mumbai Metro 4 compare to other Metro lines in length?
Operational
Metro Line 1 (Versova-Ghatkopar): 11.4 km, elevated
Metro Line 2A (Dahisar East-DN Nagar): 18.6 km, elevated
Metro Line 7 (Dahisar East-Gundavali/Andheri East): 16.5 km, elevated
Under-construction lines
Metro Line 2B (DN Nagar-Mandale): 23.6 km, elevated
Metro Line 3 (Colaba-Bandra-SEEPZ): 33.5 km, underground (except Aarey at-grade)
Metro Line 4 (Wadala-Kasarvadavali): 32.3 km
Metro Line 4A (Kasarvadavali-Gaimukh): 2.7 km
Metro Line 5 (Thane-Bhiwandi-Kalyan): 24.9 km, elevated+underground
Metro Line 6 (Swami Samarth Nagar-Vikhroli EEH): 15.3 km, elevated
Metro Line 7A (Gundavali-CSMIA Airport): 3.5 km, underground
Metro Line 9 (Dahisar East-Mira Bhayandar): 11.4 km, elevated
Metro Line 10 (Gaimukh-Shivaji Chowk, Mira Road): 9.2 km, elevated
Metro Line 11 (Wadala-CSMT): 12.7 km, elevated+underground
Metro Line 12 (Kalyan-Taloja): 20.8 km, elevated
Proposed Lines
Metro Line 8 (CSMIA-Navi Mumbai International Airport): 35 km, elevated+underground. While 9.25km is likely to be underground, 25.63 km will be elevated.
मेट्रो लाईन ४ साठी एक ऐतिहासिक क्षण !एमएमआरडीएने कापूरबावडी जंक्शनजवळ स्टील स्पॅन यशस्वीरित्या बसवला आहे, हा स्टील स्पॅन मेट्रो लाईन ४ कॉरिडॉरच्या प्रगतीतील एक महत्त्वाचे पाऊल आहे!
फक्त २ रात्रीत हे काम पूर्ण करण्यात आले. वर्दळीच्या रस्त्यावर ४८ मीटर लांबीचा स्टील स्पॅन उचलून… pic.twitter.com/gPc0sI954h
— MMRDA (@MMRDAOfficial) July 19, 2025
What are the challenges in building the longest elevated Metro line?
Acquiring land and building is tough around dense residential and commercial areas, especially near Ghatkopar, Mulund and Thane. Encroachments, relocation and rehabilitation are major issues.
Traffic disruption is another key issue as the line passes over LBS Marg and Ghodbunder Road, which are already congested. The work has also reduced road widths, adding to the traffic chaos.
Massive underground utilities (water pipelines, power cables, telecom lines) in old areas had to be identified and shifted, with trouble spots near Ghatkopar and Mulund.
Forest land and mangroves near Thane or Ghodbunder Road add to the challenges and permissions.
Such a mammoth project requires coordination between multiple departments and agencies in Ghatkopar, Kanjurmarg and Thane.

At the news desk for 17 years, the story of her life has revolved around finding pun, facts while reporting, on radio, heading a daily newspaper desk, teaching mass media students to now editing special copies …Read More
At the news desk for 17 years, the story of her life has revolved around finding pun, facts while reporting, on radio, heading a daily newspaper desk, teaching mass media students to now editing special copies … Read More
September 29, 2025, 17:04 IST
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