Hello
The Main reason for the SL Coach Trains is that many Poor & Labor's work in South India for Daily wages, coming all the way from North & North east.
for them getting a Seat in train is a Big task, they normally get cheated by Agents in Chennai, Bangalore, Hyderabad by giving them a WL Ticket, which never get confirmed.
I have...
more... many live examples, when i Normally travel from Bangalore by YPR HWH Exp & SBC GHY Exp. i saw many times these trains SL coaches are occupied by WL Tickets than Reserved tickets, those poor guys not even have money to buy a water bottle, i helped in many occasions.
if their is 3 to 4 daily trains to Northeast from South, still their will be a lot demand daily
Their is a Big Demand all time Both to HWH, GHY & Patna from Southern States.