Chennai Metro Corridor 4 double decker viaduct milestone May 2026 OMR buyer impact

On a Voyalanallur casting yard in May 2026, the final precast U-girder for Chennai Metro Corridor 4 rolled off the line. The number was 3,410. That is how many precast elements CMRL, L&T and the AEON Consortium had to fabricate to deliver the 26.1 km Light House to Poonamallee Bypass line. The 4 km double-decker viaduct, the first of its kind in Chennai, sits between Vadapalani and Saligramam. For Chennai buyers tracking metro premium pockets, the May 2026 milestone is the clearest signal in three years that Corridor 4 is on track. The question now is whether to enter Porur, Vadapalani or Saligramam pockets before partial elevated operations begin.

The short answer. CMRL with L&T and the AEON Consortium completed the final U-girder for Corridor 4 in May 2026, marking the construction completion of the 26.1 km Light House to Poonamallee Bypass elevated line. The 4 km double-decker viaduct between Vadapalani and Saligramam is Chennai's first such structure. Partial elevated operations are targeted for late 2026 to early 2027. For buyers, this opens a 12 to 18 month window to enter Porur (Rs 6,500 to Rs 8,000 per sq ft), Vadapalani (Rs 13,500 per sq ft) and Saligramam (Rs 9,500 to Rs 11,000) before metro arrival prices in fully.

What is Corridor 4 and which stations

Corridor 4 is one of three Phase 2 Chennai Metro corridors, running 26.1 km from Light House to Poonamallee Bypass. It has 27 stations total, with 16.02 km elevated and 10.07 km underground. The line is being constructed by CMRL in partnership with L&T and the AEON Consortium. The phase 2 total is 118.9 km of new metro corridors with 128 stations and a project budget of Rs 63,246 crore. AIIB is funding 16 percent (roughly USD 356.65 million) of the project. Key stations relevant for buyers include Light House, Mylapore, T Nagar, Vadapalani, Saligramam, Porur, and Poonamallee.

When does the elevated section open

The May 2026 final U-girder milestone marked the construction completion of the elevated viaduct, with finishing works (track laying, signalling, rolling stock testing) targeting Q4 2026 completion. CMRL is targeting late 2026 to early 2027 for partial elevated operations on the Light House to Vadapalani section. The full 26.1 km elevated corridor should be operational by mid 2027. The underground section (Poonamallee Bypass to Light House intermediate) targets late 2027 to early 2028. Buyers should plan on partial elevated operations in late 2026 to early 2027.

What does the double decker viaduct mean for Porur

The 4 km double-decker viaduct between Vadapalani and Saligramam is the first of its kind in Chennai. It combines metro rail on the upper deck with road traffic on the lower deck, freeing up surface streets. For Porur, which sits just beyond Saligramam on the Mount Road extension, the double-decker arrival means three things. First, faster commute from Porur to T Nagar (12 to 15 minutes versus the current 45 minutes by road). Second, structural easing of Mount Road and Trunk Road traffic that has constrained Porur growth. Third, a new development cluster around the proposed Iyyapanthangal interchange.

Which projects sit within 1 km of stations

Porur has 6 to 8 active residential launches within 1 km of the proposed metro station. Iyyapanthangal has 4 to 5 launches. Kattupakkam has 2 to 3 emerging projects. The pricing band runs Rs 6,500 to Rs 8,000 per sq ft for Porur and Iyyapanthangal, with Kattupakkam under Rs 7,000. Anna Nagar, which sits on a different metro corridor (Corridor 5), runs Rs 13,500 per sq ft. The Porur to Anna Nagar pricing gap of Rs 6,500 will narrow once Corridor 4 metro premium is fully priced in, expected by H2 2027.

OMR versus Corridor 4 buyer math

How TNRERA enforcement covers metro projects

TNRERA's enforcement of project-level disclosures is strong on documentation but variable on amenity and possession penalty collection. For Corridor 4 catchment projects, buyers should ask three questions. Does the project's TNRERA filing disclose metro proximity in the prospectus? Does the amenity package include metro-related claims (e.g. shuttle service)? Are possession dates linked to metro arrival? If any of these is opaque, walk back the price expectation.

What is the realistic 2026 to 2028 timeline

Late 2026: Light House to Vadapalani elevated partial operations target. Q1 2027: Full Vadapalani to Saligramam double-decker viaduct operational. Mid 2027: Full elevated 16.02 km operational. Late 2027 to early 2028: Underground 10.07 km operational. Full Corridor 4 (26.1 km) by mid 2028. Each of these dates carries 4 to 8 month slippage risk based on CMRL's Phase 1 track record. Buyers should plan their entry timing around the late 2026 to early 2027 partial elevated window for maximum capture of the metro premium runway.

Buyer checklist for Corridor 4 catchment

1. Verify walking distance to nearest proposed station (under 1 km is ideal)
2. Cross check station naming and exact location on CMRL Phase 2 map
3. Underwrite 6 to 8 month delay scenarios on metro arrival
4. Verify project TNRERA disclosure of metro proximity claims
5. Check developer's last 24 months Chennai handover quality
6. Confirm 70 percent escrow account compliance

For complementary context, see our analyses of Pink Line delivery uncertainty, school and hospital proximity premiums, and the 22 May 2026 Bengaluru flash flood checklist.

Frequently asked questions

When does Corridor 4 actually open?

Light House to Poonamallee Bypass elevated section is targeted for early 2027 operational opening by CMRL based on current viaduct progress. The 4 km double-decker section connecting Vadapalani to Saligramam should follow in mid 2027. Full corridor operational opening including the underground stretch is the late 2027 to early 2028 base case. Buyers should not underwrite 2026 operations.

Should I buy in Porur now?

Porur at Rs 6,500 to Rs 8,000 per sq ft is attractively priced relative to OMR's Rs 7,250 average, with the added Corridor 4 metro premium expected to add 10 to 15 percent over the next 24 months. For families with a 5+ year horizon, Porur is a reasonable entry point. The risk is the 18 to 24 month period of construction-related traffic on Mount Road and Trunk Road during station finishing.

Vadapalani versus Saligramam, which is better?

Vadapalani has more density and an established commercial profile, with prices in the Rs 13,500 per sq ft band reflecting that maturity. Saligramam offers better entry price at Rs 9,500 to Rs 11,000 and is the next stop on Corridor 4. For first-time buyers, Saligramam offers better headroom. For families prioritising proximity to schools and hospitals, Vadapalani is the safer bet.

Will OMR or Corridor 4 finish first?

Likely yes. Corridor 4 (Light House to Poonamallee) is targeting late 2026 to early 2027 partial elevated operations with the double-decker section. OMR Corridor 5 has been delayed multiple times and is now targeting 2028 to 2029. For buyers prioritising metro arrival timing, Corridor 4 currently has the cleaner schedule, though both can slip.

Last updated 25 May 2026. By the PropNewz Team.