* SECR mainline par about two-third trains are freight and one third are pax. trains. The one-third pax trains may be eating up about half of sectional capacity due to much higher priority accorded to them.
* If DFC is strategically constructed along the route,
(1) where trains have more than 3 times freight capacity per train than the conventional freight train (15000T against about 4500-5000T), and
(2)...
more...

trains operate at 3 times the average speed of current freight trains i.e. 75kmph against 25 kmph and twice the mps 100kmph against 50-60kmph at present, and
(3) freight trains shall take up 100% of the sectional capacity of the corridor against (about 50% currently) and
(4) if the DFC (as per current practice) is constructed with much lesser curvature and track geometry with advanced signalling resulting in almost no speed restrictions (on mps) resulting in increasing of thruput by about 25%,
(5) the carrying capacity of DFC shall be 3x2x2x1.25 or roughly 16 times of a double line carrying mixed traffic.
(6) Even if we consider partial tripling of the route we can say that freight capacity of the route shall increase by 10-12 times the freight capacity of current route and shall be enough to take care of traffic for very long time to come.
* I wish in long term say after 20 yrs there should be 6 tracks on the Mumbai-Howrah route, i.e.
2 tracks for Conventional trains with 130/160kmph potential (existing track after upgradation),
2 tracks for 100/110kmph DFC and
2 tracks for 320/350kmph High Speed Corridor
* How the things unfold in future, only time will tell!