The Golden Quadrilateral connects Delhi, Kolkata, Mumbai and Chennai.
The improvements includes 744 route-km of the Golden Diagonal, including the 234km Balharshah - Kazipet and 510km Kazipet - Vijayawada - Gudur sections, as well as 536 route-km of the Chennai - Mumbai Golden Quadrilateral line, including the 281km Renigunta - Gooty and 255km Gooty - Wadi sections.
Line speeds on the Vijayawada - Duvvada section have not yet been increased but signalling improvements are underway. Speeds have already been increased on the 132km Secunderabad - Kazipet section.
“The enhanced speed limits could be achieved due to the systematic and planned strengthening of tracks and infrastructure by removing bottlenecks in these sections at a fast pace,” the Ministry of Railways says.