The Chennai Metro Rail Limited conducted a trial run after the elevated viaduct from Porur to Vadapalani was completed. The section includes a 4-km double-decker line from  Alwarthirunagar to Alapakkam  

https://www.thehindu.com/news/cities/chennai/chennai-metro-rail-train-chugs-along-from-porur-to-vadapalani/article70497617.ece