Over the past decade, increased congestion and population density in Mumbai has had a significant impact on the quality of life. Transportation has been one of Mumbai’s biggest problems. The city, with its present population of over 12 million, generates about 14 million trips a day, with about 88 per cent of the, trips catered to by the suburban railway and the public transport bus services provided by Bombay Electricity Supply & Transport (BEST). The existing Suburban Rail Service carries about 6 million passengers every day, while the public bus transport system carries about 4.5 million passengers every day. Trains designed to accommodate approximately 1700 passengers, carry roughly 4500 passengers during the peak hours. The population growth in city has resulted in the vehicular population increasing from 0.15 million in 1971 to 1.29 million in 2001. The ever growing vehicular and passenger demands, coupled with constraints on capacity augmentation of the existing network, have resulted in chaotic conditions during peak hours. The resultant congestion has led to a degrading quality of life coupled with increased pollution levels. The linear geography of Mumbai has also acted as a constraint in the horizontal expansion of the city resulting in further congestion during the peak hours. Various projects have been proposed and are currently underway for the development of Greater Mumbai. Some of these are:

These projects are expected to improve traffic conditions within Mumbai. However, with the population of Mumbai expected to grow at a rate of 3.1% per year to 16 million by 2011, expansion of the city across the mainland would be inevitable to ease congestion. In the absence of such a development, the exploding population will have only two equally unpalatable alternatives open – either to expand into the far flung suburbs in the Mumbai Metropolitan Region outside of Greater Mumbai, from which commuting to Mumbai would be synonymous with long distance travel; or retain the population within the already congested regions, which would lead to the population density rising well above saturation level. One way to prevent the existing conditions from worsening is to expand of the city on the mainland across the Arabian Sea, which to a limited extent, has already occurred in the northern half of Navi Mumbai. For this development to take place, it would be important to provide additional access from Mumbai to the southern half of Navi Mumbai. The proposed Mumbai Trans Harbour Link will therefore serve not only as an economic gateway to Navi Mumbai but also a panacea to the problems faced by Mumbai. The link will also strengthen the economic integration of Mumbai Island and mainland Mumbai. At present, there are two road links connecting Mumbai to Navi Mumbai:

Both these links are approaching saturation point and are not equipped to meet the combined future projected traffic of approximately 2,21,000 PCUs by 2011, thereby necessitating creation of additional links to meet traffic growth. In this context, the proposed Mumbai Trans Harbour Link has become a necessity. A number of developmental initiatives proposed in the Navi Mumbai region will not only give rise to additional traffic movement but also accentuate the need for greater economic integration of Mumbai with mainland. Some of the key infrastructure facilities proposed being developed are:

Navi Mumbai is also well connected through rail and road links with Pune, Nasik and Thane, indicating the potential for the region to develop into a satellite city to Mumbai in a fashion similar to the emergence of Gurgaon and Noida as satellites to New Delhi. CIDCO has prepared a master plan for the development of Navi Mumbai. Current development covers only the northern half of Navi Mumbai. The southern half is still untapped, principally because of the lack of easy access to Mumbai city. The southern half of Navi Mumbai with over 2,500 hectares of land available for housing presents an opportunity to decongest Mumbai. In this context, the proposed Mumbai Trans Harbour Link (MTHL) connecting Sewri to Nhava Sheva is expected to be a catalyst of development of the city by promoting horizontal growth as against the vertical growth experienced over the past few years. The link will help reduce the problems of congestion and pollution in Mumbai. Apart from the beneficial impact of the MTHL on connectivity, population dispersal and savings to commuters, other project beneficiaries include Mumbai Port Trust, JNPT, Navi Mumbai Municipal Corporation, CIDCO, MMRDA, Navi Mumbai SEZ and various industries in the hinterland.

The need for this link has been endorsed time and again by various traffic and transportation studies conducted for Mumbai over the years as given below:

The alignment of the bridge was initially proposed by M/s Peter Frankel & Partners, UK in 1982 after studying various alignment options including tunnels. The alignment was shifted southwards in order to comply with BARC’s requirement by the Expert Committee appointed by Government of Maharashtra in 1984. This alignment was further modified by CES to save mangroves on either side of the link, large skew crossings of submarine pipelines and to satisfy the development plan finalized by the City and Industrial Development Corporation Limited (CIDCO). The alignment has received approval from the Prime Minister’s Office (PMO), New Delhi.

The Project consists of construction of a 8-lane bridge across the deep sea through the Mumbai Harbour and connects to local road networks through approaches / interchanges at both ends. The interchange on Sewri side is proposed to be taken up separately and is not covered in this contract while a trumpet interchange is proposed on mainland for dispersal of traffic to National Highway 4B. The total length of the link will be 22 km and will consist of approach roads, viaducts on intertidal zone, bridge across deep sea and interchange at Chirle.

The estimated base construction cost of the project based on experiences of similar bridges in India is approximately Rs. 40,000 million. This includes the cost of approaches, the bridge across the sea, bridge furniture, ancillary structures, traffic surveillance, illumination and environmental mitigation measures, toll plaza, parking, etc. It also covers charges on account of design, supervision, and administration by MSRDC, contingencies and the like, with provision for utility diversion, new construction and other works. The above cost is based on 2004 prices.