It covers a distance of 1,281 kilometres (796 mi) across Maharashtra, Karnataka, Telangana, Andhra Pradesh and Tamil Nadu.

The 1,281 km (796 mi)-long trunk line, amongst the long and busy trunk lines connecting the metros, has been treated in more detail in smaller sections: The first passenger train in India from Chhatrapati Shivaji Maharaj Terminus in Mumbai to Thane ran on 16 April 1853 on the track laid by the Great Indian Peninsula Railway.

The GIPR line was extended to Kalyan in 1854 and then on the south-east side to Khopoli via Palasdari railway station at the foot of the Western Ghats in 1856.

While construction work was in progress across the Bhor Ghat, GIPR opened to public the Khandala–Pune track in 1858.

[1] The Western Ghats presented a big obstacle to the railway engineers in the 1860s.

MR extended its trunk route to Beypur / Kadalundi (near Calicut) and initiated work on a north-western branch out of Arakkonam in 1861.

[5] Railway electrification in India began with the first electric train, between Bombay Victoria Terminus and Kurla by the Great Indian Peninsula Railway's (GIPR) on 3 February 1925, on 1.5 kV DC.

[17] Mumbai CSMT, Pune, Solapur and MGR Chennai Central, on this line, are amongst the top hundred booking stations of Indian Railway.