 The Ahmedabad-Mumbai line runs near the coast and therefore, has more bridges, and parts of it are in backwaters or forests.The 1987 RDSO/JICA feasibility study found the Mumbai-Ahmedabad line to be the most promising.To put the construction in perspective, in the period 2005-09 Indian Railways took on construction of 42 completely new conventional lines, a total of 4060 km at a cost of ₹167 billion (US$3.63 billion), or ₹41 million per km (US$0.89 million/km).