No its not fastest. Ajmer shatabdi and Jaipur Delhi Double Decker run with more MPS as they both get 4500 HP TKD WDP4B/D but ADI SJ Rajdhani gets VTA WDM3D 3300 HP. I have travelled in 12985 DD in Oct 2014 from JP to GGN and DD reached up to 120 kmph between JP Alwar Rewari with TKD WDPD 40109 in charge.