The eagerly anticipated Metro 3 subterranean line underwent its first long-distance test. A train travelled eight kilometres (km) through six stations from MIDC to Vidyanagari before returning to Seepz station, reaching a distance of about 17 kilometres. The first phase of the Aarey-Cuffe Parade corridor, also known as the Aqua Line, from Aarey to BKC is set to begin operation before the end of the year, according to metro authorities.

Along with pictures of the inside of the train, a video of the tunnel as seen from the driver's cabin of the running train was tweeted. The tweet received thousands of likes and hundreds of retweets. "The milestone demonstrates the culmination of infrastructure work related to tracks, overhead contact system (power line for trains), rolling stock and structures like platform screen doors," a Mumbai Metro Rail Corporation (MMRCL) spokeswoman said.

On the 12 kilometre Aarey-BKC section, MMRCL intends to operate 110 services, with a travel time of 25 minutes when stops are taken into consideration. For the 110 services, nine trains will be needed, of which eight have already been delivered and the other three are anticipated by the end of the month.

On 30 August of last year, Eknath Shinde, Chief Minister, and Devendra Fadnavis, Deputy Chief Minister, launched short-distance testing runs for the first prototype rake. A 3 kilometre section between Sariput Nagar in Aarey and Marol Naka was used for the experiments.