According to officials, the 58.19-km Namma Metro Blue Line, also known as the Outer Ring Road-Airport Metro corridor, will connect Central Silk Board Junction in south Bengaluru to Kempegowda International Airport in the north. Bengaluru metro blue line trial runs advance towards mainline testing According to officials, the 58.19-km Namma Metro Blue Line, also known as the Outer Ring Road-Airport Metro corridor, will.