Updated 27 October 2026. Below: what is being built, the timeline and how the dates have moved, the other airport-road works near the Yelahanka air force station, and what the project means for buyers in Devanahalli, Bagalur, Yelahanka and Sadahalli.

What is the Sadahalli underpass?

  • Location: Sadahalli Junction on Ballari Road, the main road to the airport (Urban Acres, 13 October 2026).
  • Size: six lanes. Length is reported as 750 m (NewsFirst Prime; Urban Acres) or about 700 m (The Hans India); the difference may be ramps.
  • Cost: about ₹35 crore (NewsFirst Prime; The Hans India).
  • Contractor and method: Vidya InfraBuilt Pvt Ltd, with a cut-and-cover design that had been approved (The Hans India, 8 July 2026).
  • Purpose: airport-bound traffic passes without stopping; people from Sadahalli and nearby areas heading to the city or Devanahalli can still cross (Urban Acres).
  • Corridor: the Hebbal–airport stretch is about 22 km and Sadahalli is its only remaining signal (Perfect Neighbourhood, 10 July 2026).

Sadahalli underpass completion date

NHAI now expects completion by mid-2027 (Urban Acres; NewsFirst Prime, 13 October 2026). In July the plan was more ambitious: preparatory work and service-road widening from two to four lanes over the monsoon, excavation from September, and opening before Aero India in February 2027 (The Hans India, 8 July 2026). Traffic police had approved night work from 11 pm to 5 am for 15 months from 1 July (The Hans India).

Our reading: the window has moved by a few months, which is normal for a junction carrying airport traffic. A mid-2027 opening is the date to plan around; February 2027 now looks unlikely.

Will there be diversions on airport road?

Not yet at Sadahalli. Traffic police said no diversions had been imposed so far, and the work is being done in phases because of heavy traffic (Urban Acres, 13 October 2026). The July plan relied on widening the service roads first so that traffic could shift off the main carriageway (The Hans India; Perfect Neighbourhood). If you commute to the airport, allow extra time on the service roads at night when work is under way.

Other airport-road works near the IAF station, Yelahanka

  • Service road between IAF Gates 1 and 2: the first 240 m is complete, with utility and compound works (Urban Acres; NewsFirst Prime, 13 October 2026).
  • Gates 2 to 3: in progress, targeted for December 2026 (Urban Acres).
  • Cut-and-cover work on this stretch: to begin after the Aero India show in February 2027 (Urban Acres).
  • Domestic-side service road, Gates 5 to 6: starts once BMRCL hands over encumbrance-free land to NHAI (Urban Acres).

How the airport metro fits in

The Blue Line's Hebbal–airport section is the other half of the airport-corridor story. As of 22 October 2026, U-girder erection on that section was 95% done, station entry and exit work 41% and 18.6 of 52.9 track-km laid; the state targets the airport–Hebbal stretch by end-2027 (GBA and BMRCL releases via NammaWard, 22 October 2026). Stations on this stretch include Kodigehalli, Jakkur Cross, Yelahanka, Bagaluru Cross, Doddajala and the airport terminals (Wikipedia, Blue Line). So road relief comes first, around mid-2027, and metro service roughly six months later if both targets hold.

What does the Sadahalli underpass mean for property buyers?

  • Commute reliability, not distance: removing one signal will not shorten the 22-km drive, but it removes the main point where the airport road stops. That matters most for people who drive to Hebbal and the city every day from Devanahalli, Bagalur and Sadahalli.
  • Pricing context: ANAROCK lists three large north-side launches in Q3 2026: Prestige Parklane in Devanahalli (1,788 units, ₹11,400 per sq ft), Bhartiya Garden Hill Phase I & II in Bagaluru (1,554 units, ₹11,500 per sq ft) and Embassy South Reserve in Tharahunise (855 units, ₹13,500 per sq ft) (ANAROCK Bengaluru Q3 2026). North Bengaluru supplied 46% of the city's launches that quarter.
  • Do not pay twice: many airport-belt launches already price in the airport road, the metro and the office parks. A signal removal is a modest addition, not a reason for a higher quote.
  • Check the service road: homes and shops on Ballari Road's service roads will live with the construction phases until 2027. Look at access during peak hours.
  • Rents: airport-belt rental demand still depends on jobs nearby. See our reality check: Devanahalli Rental Yield in 2026: A Reality Check for Airport-Belt Investors.

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