A technical report from the Indian Institute of Science (IISc) has deemed the double-decker component of Namma Metro’s Phase 3 project economically unsound, estimating its economic internal rate of return (EIRR) at just 9.07%—well below the accepted benchmark of 14%.
Key Findings of the IISc Report
Prepared by Professor Ashish Verma of IISc, the report calculates the EIRR for Phase 3 at 9.07% when the double-decker structure is included. In contrast, if the elevated road component is removed, the EIRR rises sharply to 18%, making the project financially viable without the double-decker design.
The double-decker plan, which combines an elevated metro corridor with a road flyover, has been a subject of debate due to its high costs and structural complexities. The IISc analysis highlights that the additional expenditure and operational challenges do not justify the marginal benefits.
Impact on Bengaluru’s Urban Mobility
Phase 3 of Namma Metro is a critical expansion aimed at decongesting Bengaluru’s traffic. However, the report’s findings may prompt a rethink among policymakers. Professor Verma’s study suggests that a standalone metro corridor would yield significantly higher economic returns, aligning with global best practices for transit projects.
According to the report, the double-decker design not only inflates construction costs but also increases maintenance and safety risks. The EIRR benchmark of 14% is a standard threshold for infrastructure projects in India, and falling below it indicates that the investment is not economically justified.
Reactions from Officials
Bangalore Metro Rail Corporation Limited (BMRCL) officials have not yet issued a formal response, but sources indicate that the report will be reviewed by the state government. The Karnataka government has already invested significant resources in the Phase 3 planning, and any major redesign could delay the project.
Urban transport experts have long argued for prioritizing cost-effective solutions. The IISc report adds weight to calls for scrapping the double-decker component, which was originally proposed to optimize land use along congested corridors.
Next Steps for Phase 3
The report is expected to influence the final decision on Phase 3’s alignment. With an EIRR of 18% for the metro-only option, the economic rationale is clear. However, political and bureaucratic hurdles may delay a course correction. The state government is likely to seek further consultations before amending the project design.
