i have been in a rajdhani from kanpur delhi during fog time. the arrival time at kanpur was perfect to the time and the fog started somewhere after aligarh. by the time we reached ndls it was 5 hrs late. aligarh delhi is approx. 140kms (almost equivalent to mtj)
even the fastest bpl shatabdi comes late by more than 3 hours.
its an experience to be in zero visibility fogs and sometimes the trains are held up in the middle of nowhere due to zero visibility or signals.
last...
more... year they experimented with fog safe devices in ASR route and it was a failure on many counts. gps did not work and they withdrew the experiment as it was a total failure and this year again, once again they are experimenting the fog safe devices with some improvements and again on a gps based device. let us hope at least this time it works and v passengers have some improved punctuality, at least not to that bad extent.