Noise Level Forecasting for Chennai Metro Rail – Phase II (Corridor 3, 4 and 5)

Noise level forecasting was carried out for Chennai Metro Rail Limited (CMRL) , a joint venture of the Government of India and Government of Tamil Nadu with equal equity ownership, is responsible for implementing, operating, and maintaining the city’s metro system. CMRL developed the Comprehensive Mobility Plan for Chennai Metropolitan Area (CMA) in 2015 to identify the present and future mobility patterns of CMA. The detailed study identified three corridors (corridors 3, 4, and 5) for the second phase of the Chennai Metro Rail to alleviate CMA’s transportation capacity constraints.

• Proposed alignment of Corridor-5 starts from Madhavaram as underground and heads in south direction upto Sholinganallur. Total length of the corridor is 47.0 km including 41.17 km elevated and 5.83 km underground section..
• Switch Over Ramp
• Switch over Ramp (SWR) have been provided at three locations viz a viz. after Madhavaram station, second between Retteri junction & Kolathur Junction and third between Nathmuni & Anna Nagar Bus Depot.
• 48 stations have been proposed in Corridor-5 consisting of 41 elevated stations, 1 at-grade station and 6 underground stations.

As a part of the project a general screening assessment was performed by CMRL. The General Noise Assessment is used to examine potentially impacted areas identified in the screening step by examining the location and estimated severity of noise impacts. This procedure considers noise source and land use information likely to be available at an early stage in the project development process. Estimates are made of project noise levels and of existing noise conditions to model the location of a noise impact contour that defines the outer limit of an impact corridor or area. This modelling method uses transit-specific noise and adjustment data (in tabular and graphical form) for the noise computations.

Conclusion of the Study

The baseline noise study was carried out at 12 residential locations along the alignment of CMRL phase 2 corridor- 5.

• The results of noise modelling revealed that, in most case the predicted noise levels were within the baseline noise levels and certain locations will have marginal impacts due to increase in noise levels due to proposed activities.
• Mitigation measures are provided to minimise and control the marginal impacts
• Construction noise is expected to create an impact and appropriate mitigation measures shall be taken as per the criteria and impact shall be reduced.
• As per the CMRL SHE manual and Detailed Project report, there would be no construction activity that would take place during night.