Railway Minister Mamata Banerjee has inaugurated the 6 kms strech of Kolkata Metro Railway from Tollygunge to Garia Bazar. It was announced in 1999. With the expansion, the 22.50 km distance between Garia Bazaar (the southern-most Metro station) and Dumdum (the last station located in the city's extreme northern fringes) would be covered in just 41 minutes.
Some more points:
Tollygunge Metro station after late Bengali idol Uttam Kumar
Garia Bazar station was renamed after noted Bengali poet Kazi Nazrul Islam.
distance of 22.5Km coveredin 41mins means an avg. speed of 30Km/hr that's not that great
the buses in chennai go at a better speed than that 