IRI - चाहे कितने भी हों मतभेद, फिर भी हम परिवार एक - Dr. Abhishek Rai

There can be many reasons for buffer time
eg. signal failure at any point during journey
Locomotive failure
OHE failure
speed restrictions
unscheduled...
more...

halt at intermediate station allowing faster trains to pass through
and many more ...
A few months back while I was travelling by a train it was delayed by half an hour
The reason ?
It was shocking and unbelievable ...
A man had committed suicide travelling by general compartment.
It was noticed only the next day .
Not to suggest that such things are common but this was truly not imaginable even by die hard pessimists
Not all reasons can be documented but yes ...
a travelling time of 2 hrs for 10 kms distance is streching things a bit too far