BMRCL starts soil testing for Namma Metro Red Line

Bangalore Metro Rail Corporation Limited (BMRCL) has started a geotechnical investigation along Sarjapur Road for the proposed 37.8 km phase 3A corridor of the Bengaluru Metro, also known as the Red Line, which is planned to connect Sarjapur in southeast Bengaluru with Hebbal in the north.

The survey will assess the properties of the soil and bedrock along the proposed route before construction begins. The findings will help engineers evaluate the ground conditions and determine the technical requirements for the construction of the above-ground and underground portions of the metro corridor, according to BMRCL officials.

Namma Metro Phase 3A (Red Line): Key Details

Route: Hebbal to Sarjapur Road

Route length: 37.8 km

Route composition: 23 km above ground and 14 km underground

Major Areas Covered: Hebbal, Central Business District, Koramangala, Sarjapur

Latest estimated price: ₹25,999 crore

Speaking to The Hindu, a senior BMRCL official said, “The study will provide basic information on soil stability, geological formations and other soil conditions along the route. These findings will guide decisions on foundation depth, structural design and construction requirements for the metro pillars, which will help ensure safety and stability of the infrastructure.”

Meanwhile, the proposed project is awaiting approval from the Union government, officials confirmed. The state government has submitted a detailed project report (DPR) for the corridor, but the Center has not given a timeline for granting its approval.

As reported by The Hindu earlier, the Ministry of Housing and Urban Affairs (MoHUA) informed Parliament in August that the project was still undergoing detailed review. Its approval would depend on the outcome of the assessment of feasibility and availability of financial resources.

The clarification was given in a written reply to a question raised by Ajay Maken in the Rajya Sabha. The ministry said that metro rail projects require significant capital investment and must undergo a comprehensive assessment in line with the Metro Rail Policy 2017 before approval. As a result, it said no specific timeline could be given for sanctioning the proposed corridor.

The project is under long-term review and its estimated costs, especially the expenses associated with underground construction, are being discussed between the state and union governments.

In response to concerns raised during the appraisal process, BMRCL undertook a cost-cutting exercise that included changes to underground station designs, alignment adjustments and station location adjustments. The company also hired an engineering consultancy to review project estimates and identify opportunities to reduce expenses without compromising operational requirements.

According to BMRCL officials, the revisions included shortening the lengths of metro stations, comparing construction costs with those of similar metro projects and modifying various technical specifications. These measures significantly reduced the estimated cost of the project.

Once completed, the Red Line is expected to improve connectivity between Hebbal and Sarjapur Road and connect important residential and commercial areas, including Koramangala and Bengaluru’s central business district, as well as the city’s south-eastern IT corridor.

Published – 15 Oct 2026 06:00 IST