Model Bengaluru’s bold 16.75 km tunnel street challenge (TRP) connecting Hebbal and Silk Board junction is within the eye of a storm. From specialists on the Indian Institute of Science (IISc) Bengaluru calling it unscientific to the federal government’s personal suppose tank Directorate of City Land Transport (DULT) observing that it doesn’t align with metropolis’s Complete Mobility Purpose (CMP), the challenge, constructed at a price of Rs 17,698 crore, is on the receiving finish of extreme criticism.
BS Prahallad, technical director of B-SMILE (Bengaluru Sensible Infrastructure Restricted), a particular objective automobile executing essential infrastructure initiatives in Bengaluru, speaks to The Indian Categorical, breaking down the genesis of the tunnel street challenge, environmental impression, monetary fashions, and addresses among the key criticisms over the challenge.
Excerpts from an interview.
Q. What’s the genesis of the tunnel challenge?
Prahallad: The tunnel challenge addresses the lacking connectivity between Silk Board and Hebbal. Elevated corridors exist already on Hosur Highway and Bellary Highway, however the central NH stretch by town was de-notified. Widening or constructing elevated roads right here confronted main challenges—land acquisition, displacement, and large-scale tree elimination.
Geological research, together with these by Belgian specialists, confirmed that Bengaluru’s rocky terrain is appropriate for tunnelling. Impressed additionally by Mumbai’s coastal street tunnel, this challenge was chosen as a hazard-free resolution to combine town’s north–south and east–west corridors.
Q. IISc Bengaluru has referred to as the challenge unscientific. What’s your response?
Prahallad: IISc advised that tunnels could solely shift visitors. Nevertheless, our detailed visitors examine supplies an end-to-end resolution that disperses visitors fairly than relocating it. Town’s street area has remained fixed whereas autos have grown exponentially.
Alongside the tunnel, multi-modal choices like suburban rail, Metro, and pod taxis are being developed. With TOD encouraging vertical development, personal automobile utilization is anticipated to peak round 2035 and regularly decline. Bengaluru is just not new to tunnelling—Metro has already executed 40–45 km efficiently.
Q. How was the 40 per cent VGF determine arrived at?
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Prahallad: Authorities coverage caps VGF at 40 per cent for BOOT (Construct-Personal-Function-Switch) initiatives. Right here, we’re adopting a modified BOOT mannequin—40 per cent fastened VGF with a versatile concession interval. Monetary evaluation by BCG confirmed this as essentially the most viable choice.
The concessionaire brings 60 per cent funding, whereas the federal government’s share is borrowed from HUDCO and repaid by Premium FAR charges collected by BBMP. It isn’t straight funded by Bengaluru’s frequent taxpayers, as a substitute not directly. If the concessionaire recovers prices earlier, the challenge reverts to the federal government sooner.
Q. DPR signifies over 20 potential gridlock factors. How will you handle this?
Prahallad: We’re buying about 40.6 acres for ramps and shafts—28.5 acres of presidency land and 11.5 acres of personal land. This ensures we don’t squeeze visitors into the present street width. Most shaft websites are positioned on authorities lands, akin to KIADB, Race Course, and Lalbagh, thereby minimising the impression on personal land.
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By planning entry and exit ramps with satisfactory area, we goal to forestall bottlenecks. We have now additionally allotted Rs 800 crore for land acquisition, as towards the preliminary estimation of Rs 600 crore.
Q. The DULT says the challenge doesn’t align with the Complete Mobility Plan. What do it’s a must to say?
Prahallad: We studied the DULT’s remarks rigorously. The first purpose for proposing this tunnel is that the very best visitors density is alongside the north–south and the east–west corridors, which have been as soon as a part of the Nationwide Freeway community. The motion of individuals from the southern elements of town to the north, and vice versa, can’t be averted—it’s indispensable. That’s the reason this hall has been recognized as a principal proposal.
Q. Has the challenge obtained Part 19 BMLTA approval?
Prahallad: Sure, the federal government consulted the Bengaluru Metropolitan Land Transport Authority (BMLTA), however since guidelines are usually not totally framed, the company directed us to take an acceptable resolution on the authorities degree. Following this, the City Improvement Division fashioned a committee headed by a BMRCL govt.
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The committee reviewed feasibility, alignment, value estimates, and even the variety of geotechnical surveys finished (18 as a substitute of 14). Their last advice was clear—the challenge is possible, however to permit a ten–15 per cent cushion for unexpected circumstances.
Q. Will tunnel congestion worsen with extra vehicles sooner or later?
Prahallad: Our projections present automobile development at 7 per cent yearly for the primary six years, 5 per cent for the subsequent seven years, and 4 per cent from yr 15 onwards. Personal automobile use will peak by 2035 however then decline with higher public transport and TOD. By 2040, the visitors development charge is anticipated to stabilise at simply 4 per cent, making tunnel congestion manageable.
Q. Are autos and two-wheelers permitted?
Prahallad: No. That is an NHAI directive, not a state resolution. Two-wheelers are barred from tunnels throughout India, together with Mumbai, for security, pace, and safety causes.
Q. What about buses?
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Prahallad: Sure, buses shall be allowed. Early monetary fashions excluded them from income calculations, which triggered confusion. The ultimate DPR makes it clear—public buses, mini-buses, and electrical buses will use the tunnel.
Q. Will buses get a devoted lane?
Prahallad: The design supplies a ten.5m-wide, 3-lane carriageway with footpaths and refuge bays. If bus demand grows considerably, a devoted bus lane may be launched. The design leaves this flexibility open.
Q. Why retail and business areas at shafts?
Prahallad: Shaft areas would stay underutilised if used just for air flow. By including retail, we encourage transit-oriented improvement and create commuter-friendly hubs. It’s much like multiplexes in malls—mobility mixed with facilities attracts extra customers and prevents these areas from going to waste.
Q. How will you keep away from dangers to Metro constructions?
Prahallad: The tunnel is 120 toes deep, whereas Metro tunnels are solely about 60 toes. Our alignment ensures a minimum of “2D” clearance beneath Metro strains, and extra engineering care shall be taken at essential crossings. Such factors will obtain extra engineering care in the course of the development part. So there isn’t a purpose for apprehension.
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Q. Why is there no Atmosphere Impression Evaluation (EIA), particularly after the Silkyara tunnel collapse in Uttarakhand?
Prahallad: Underneath the Centre’s 2006 notification, no EIA is required. Extra importantly, Bengaluru’s laborious granite rock is secure and conducive for tunnelling, not like the delicate geology in Uttarakhand, which is likely one of the rarest of the uncommon circumstances. Nonetheless, security precautions are being constructed into the challenge.
Q. What about environmental issues at Lalbagh?
Prahallad: The tunnel runs deep underground and gained’t disturb floor ecology or groundwater. Precautions shall be taken, however related Metro tunnelling of 40–45 km in Bengaluru confronted no objections.
Q. The consultants chosen for DPR and feasibility are beneath scrutiny. Why was such an organization chosen?
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Prahallad: As per the legislation of the land, any occasion has the best to defend themselves. On this case, the businesses in query have obtained keep orders from courts towards blacklisting from numerous entities and defended themselves legally. Till the ultimate judgment, we’re certain by the legislation to permit their participation.
Q: How was the response to the pre-bid assembly with development firms?
Prahallad: Very constructive. All main Indian infrastructure firms participated, together with curiosity from worldwide gamers by Indian partnerships. No main objections have been raised—solely requests for extra time to review particulars, for which now we have prolonged the tender receipt bids until August 21.
Q. The toll of Rs 330 (round Rs 20/km) is being criticised. Is it justified?
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Prahallad: First, tolling will begin solely after challenge completion—round 2030–31, not at present. Second, solely tunnel customers pays; floor roads stay toll-free. The charges comply with the components beneath the state authorities’s 2008 notification, which is utilized throughout the state. This isn’t distinctive to our challenge—related tolls are already collected on elevated corridors in Digital Metropolis and NICE infrastructure corridors.
Q. The DPR mentions a 51-month deadline. Is that sensible?
Prahallad: Sure. With six tunnel boring machines (TBMs), the tempo is about 100m/month, which supplies a 48–63 month timeline. If we use eight high-speed TBMs, the progress may double to 200m/month, lowering the timeline to 36 months for boring, plus ending work. Tunnelling is now commonplace expertise worldwide, and prices and timelines enhance with each challenge.