a regular survey, achieves greater accuracy and helps protect against false claims for compensation. In March 2017, the MMRDA stated that it was conducting a pre-feasbility study on extending the line from Wadala to Mumbai General Post Office in South Mumbai, via the Mumbai Port Trust. The proposed extension is estimated to cost 300 crore per km. In October 2018, the MMRDA announced that it would construct Metro 4 along with three flyovers to ensure smooth flow of traffic, with the metro running on the upper deck of the flyover. The three flyovers will be built at Bhayander Pada, Kasarvadavli and Anandnagar near Ghodbunder. In May 2019, MMRDA Metropolitan Commissioner R.A. Rajeev announced a modified plan to use Siddharth Colony as the interchange station with Line 2. The original plan had proposed to use the Eastern Express Highway station on Line 2B and Siddharth Colony on Line 4 as the interchange stations. However, the two stations are approximately 480 metres away from Siddharth Colony and the change was made to simplify passenger transfers. Construction A consortium of DB Engineering, Louis Berger and Hill International was awarded a project management and construction management services contract for the Metro 4 project in April 2018. The MMRDA invited bids for civil work on the corridor on 4 January 2017. The tenders for construction of viaducts and stations were divided into five packages - Wadala to Amar Mahal Junction, Garodia Nagar to Surya Nagar, Gandhi Nagar to Sonapur, Mulund Fire Station to Majiwada and Kapurbawdi to Kasarvadavali. Metro 4 was tendered alongside Metro 2B. L&T, Afcons Infrastructure, Tata, NCC and JMC, Reliance Infrastructure-RdE, Wenig Incorporation, JKumar Group, ITD Cementation, CHEC-TPL bid for packages on both Metro 2B and Metro 4. A total of 11 firms and/or consortia submitted bids for the two lines, two of whom (Simplex Infrastructures and a consortium of GHEC-RCC-JV-China) bid exclusively for Metro 2B packages. The construction work was divided into five packages and awarded through the engineering, procurement and construction (EPC) model in April 2018. A joint venture between Reliance Infrastructure and Italian firm Astaldi S.p.A. was awarded three packages between Kasarwadavali and Wadala worth . The contract for the remaining two packages, worth a combined , was awarded to a joint venture between Tata Projects Limited and China Harbour Engineering Company. The civil work is expected to be completed in 30 months. Whereas, On the Metro 4A project,