if u want nonstop run for 11-12 hours..u better catch airways.....
in case of railways.....a stop mayb technical or commercial is required atleast in ever 400-500 kms ...
there mayb many reasons like crew change/engiene change/power change/zonal change/speed restriction, etc.+no system is prefect...der mayb a stop 4 crossing...or mayb bcoz other trains r delayed.....etc. so duronto concept is good...bcoz it allows only ened 2 end passengers 2 board the train(even half ticketers can board).....and also provides technical halts without disrupting the schedule