Mumbai, April 23 -- The Maharashtra government has approved the expansion of Mumbai Metro 5 and a new, integrated line, 5A, together forming a 34.2-km metro network across the Thane-Bhiwandi-Kalyan-Ulhasnagar belt at an estimated cost of Rs.18,130.55 crore, according to a government resolution (GR) issued on Wednesday. Originally approved in October 2017, Metro 5 was planned as a 24.9-km fully elevated corridor with 17 stations connecting Thane, Bhiwandi and Kalyan, at a cost of Rs.8,416.51 crore. The project is being implemented in two phases, of which the first phase, between Thane and Bhiwandi, spanning 11.9 km with six stations, is now in the final stages of construction. This stretch progressed faster as it did not involve major rehabilitation and resettlement challenges. The second phase, from Bhiwandi to Kalyan, has faced significant delays due to encroachments, necessitating large-scale demolition drives by the Bhiwandi municipal corporation. The 10.475-km stretch, with six stations, has seen multiple design changes and cost revisions. In June 2023, a portion of the alignment between Durgadi and Kalyan was converted from elevated to underground, resulting in a cost escalation of Rs.1,427 crore. A subsequent review in June 2025 further modified the design, with the state deciding to make the corridor partially underground between Dhamankar Naka and Temghar. The revised cost of this phase is now Rs.7,326.13 crore. In a key shift, the alignment of Line 5 has been curtailed, and the corridor will now terminate at Durgadi instead of extending up to Kalyan as originally planned. To maintain connectivity to Kalyan and beyond, authorities have introduced Metro Line 5A as a continuation of the network. The 11.83-km Line 5A will run from Durgadi through Aadharwadi and Khadakpada to Kalyan, with a further extension towards Ulhasnagar....