partially true,yes there is lot of slack time in SR,but thats due to either single line or huge slack time
talking about mdu chennai section the speeds are good but they have given huge slack time due to single line section around trichy
after doubling the whole section will speed up,i see potential of covering this 500 km strech in 7hrs
my point on...
more... giving lhb is to save maintainence and running costs{esp with HOG}