[2] The Dwarka – Barakhamba Road section of the line was inaugurated and opened to the public by the then Prime Minister of India, Dr. Manmohan Singh, on 31 December 2005.

A branch of the Blue line spanning 6.25 kilometres (3.88 mi) was inaugurated on 8 January 2010 from Yamuna Bank metro station to the Anand Vihar in East Delhi.

[6] On 9 March 2019, a 6.67 km (4.14 mi) extension of the line from Noida City Centre to Noida Electronic City was unveiled to the public.

[7] It has been proposed to extend the main line from Noida Electronic City to Sahibabad with five stations at Vaibhav Khand, DPS Indirapuram, Shakti Khand, Vasundhara Sector 5, and Sahibabad.

[8][9] Karkardooma station on the Vaishali branch of the Blue Line holds the distinction of the second highest station of Delhi Metro with a platform height of 20 metres (65 feet 7 inches).