CH NEWS BENGALURU An IIT Bombay assessment projects faster peak-hour traffic movement, while an IISc review questions assumptions behind the findings. An IIT Bombay study on the Hebbal short tunnel and elevated corridor has recommended implementing both projects, projecting improved traffic speeds and reduced delays if a substantial share of traffic shifts to the proposed infrastructure. The study, conducted by Professor Archak Mittal for Rithwik Projects Private Limited, the BDA contractor for the short tunnel, estimated that average peak-hour speed in 2027 could increase from 13.74 kmph on the existing road network to 20.64 kmph if 50% of traffic shifts to the tunnel and elevated corridor. At an 80% shift, the projected speed is 22 kmph. The study tested 50%, 60%, 70% and 80% traffic-shift scenarios based on assumptions in the project DPRs. It examined the existing road network, elevated corridor, tunnel and combined project, and recommended the two facilities together. However, the Sustainable Transportation Lab at the Indian Institute of Science (IISc) reviewed the assessment and described it as “biased in favour of building the two projects”, citing insufficient evidence for its recommendations. IISc IST Lab convener Ashish Verma questioned the traffic-diversion assumptions, calling the 50% and 80% levels “arbitrary”. He said the study did not establish the figures through a robust route-assignment methodology. The review also noted that the tunnel has 3+3 lanes while the elevated corridor has 2+2 lanes, making identical diversion assumptions questionable. It said the detailed analysis primarily covered the existing network and combined project, rather than independently evaluating each facility. The IIT-B study itself flagged a possible bottleneck where traffic from both facilities could converge downstream. It recommended traffic channelisation and at least a 250-metre gap between the structures. Prof Verma also said the assessment did not compare public transport alternatives or environmental, ecological and road-safety costs.