The bulk of the stretch is likely to be underground, leading to an escalation of cost from the original estimate of Rs. 44,000 crore.

Even as phase I of Chennai Metro Rail is finally becoming operational in segments, after six years of construction, phase II, stretching over 104.5 km with 104 stations, will soon be submitted to the State government for approval.

Officials of RITES, the organisation that has been preparing the detailed project report for the stretch, said they will submit the document in September.

“There were some delays related to traffic permissions when we conducted the surveys. Also, residents put up opposition in many areas during the survey. If Chennai Metro Rail and the State government want to make changes, then, there will be minor changes in the alignment,” an official said.

Except for the portion from Kandanchavadi bus stop to SIPCOT, the remaining portions of the three corridors will be underground. “Except for that portion, we don’t have the adequate road width to carry out elevated corridor construction in the rest of the stretch,” an official said.

There will be a huge depot located at Madhavaram Milk Colony for maintenance of stations. “Depending on the requirement, we can add another depot,” he added.

According to officials of the Chennai Metro Rail Limited (CMRL), if most of the three corridors in phase II are underground, then the cost may be revised from the existing estimate of about Rs. 44,000 crore. “It may cost about Rs. 150-200 crore per kilometre overground, whereas underground construction may cost as much as Rs. 400-500 crore per kilometre,” an official said. In this phase too, the Japan International Cooperation Agency may be providing part of the funds, he added.

Sources said the fares may be in line with the rates in phase I. For the first service between Koyambedu and Alandur, the fares range between Rs. 10-40 for the 10-km stretch.