City number five. Same rules: GHSL 2025 population (11.5 million people in a 37 × 46 km box), 14 food hotspots, 6 independent growths of 50,000 agents, and we count the people living within 800 m of a line. The sea is a wall, as in Mumbai. The real network is every Chennai Metro line open on 25 Oct 2026: Blue (Wimco Nagar to the airport), Green (Chennai Central to St. Thomas Mount) and the first Phase 2 stretch, Poonamallee Bypass to Vadapalani, which opened on 11 Oct 2026 (CMRL press release). That's 51 stations and about 69 km officially. We left out the MRTS (Beach to St. Thomas Mount) and the suburban trains: they're run by Southern Railway, and CMRL's takeover of the MRTS hasn't been signed yet (TOI). So Chennai is metro against metro, like Delhi, Bengaluru and Kolkata. See the caveats. Pick the Chennai tab in the live sim above.
| Measure | Slime mold | Chennai Metro |
|---|---|---|
| Network length | 116 km | 63 km (straight lines) |
| People within 800 m of a line | 2.99 million (26%) | 2.67 million (23%) |
| People within 800 m, per km of line | 25,800 | 42,200 |
| Same length: people within 800 m | 1.74 million (58 km) | 2.67 million (63 km) |
| Share of its network within 1 km of the other's | 13% | 24% |
The metro wins clearly. Trim the slime to about the metro's length and it reaches 35% fewer people. The nearest trim is 58 km, a bit shorter than the metro's 63 km, but even the next step, 75 km (longer than the metro), reaches only 2.22M, still 17% short. The two networks barely agree: only 13% of the slime runs within 1 km of a metro line, the lowest overlap in our league. The metro is a cross through the centre plus a new arm to the west. The slime builds a hub near Central, then a long coastal spine north to Tiruvottiyur and a big southern arc through Adyar, Madipakkam and Chromepet towards Tambaram, where the metro doesn't go yet.
The biggest crowds more than 2 km from any open metro line, checked against the news. Three of the four already have suburban or MRTS stations nearby, so these are metro gaps, not rail deserts.
| Hotspot (approx. centre) | People within 3 km | To nearest open line | Reality check |
|---|---|---|---|
| Chromepet | 585,000 | 3.6 km | Awaiting approval The 15.5 km Airport–Kilambakkam metro via Pallavaram, Chromepet and Tambaram was sent to the Centre in April 2025 and is still waiting for its nod (DT Next, BusinessLine). The Tambaram suburban line serves it today. |
| Madipakkam / Puzhuthivakkam | 569,000 | 2.9 km | Under construction Phase 2 Corridor 5 (Madhavaram–Sholinganallur) has stations at Madipakkam, Kovilambakkam and Medavakkam. All its precast parts are cast, but track and systems are still to come (Construction World). The MRTS reached Puzhuthivakkam in March 2026 (The Hindu). |
| Adyar / Indira Nagar | 482,000 | 4.2 km | Under construction Phase 2 Corridor 3 is tunnelling between Thiruvanmiyur and Indira Nagar (The Hindu). Phase 2 as a whole is due by the end of 2028. MRTS stations (Indira Nagar, Thiruvanmiyur) serve it today. |
| Tiruvottiyur west / Manali | 398,000 | 2.1 km | Study only CMRL invited bids in 2026 for a project report on an Assisi Nagar–Wimco Nagar extension (CMRL tender). Residents are asking for a line to Manali New Town (DT Next). |
Chennai caveats. Station data is a Wikidata snapshot taken on 25 Oct 2026 (only stations marked "in use"), checked against the news. The new Phase 2 stretch runs non-stop from Porur Junction to Vadapalani (the stations in between aren't built yet), so we drew that 6 km link by hand. Lines are drawn as straight links, so we measure 63 km against the official ~69 km. Leaving out the MRTS and suburban trains matters: the slime's coastal spine and southern arc run close to rail lines that already exist. We count residents only, so the Guindy and OMR office districts count for nothing. Chennai is one big blob of people, so it gets only 14 hotspots (lowering the threshold only added tiny peaks at the box edge), and the slime network is fairly tree-like.
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