Major blockage for High Speed: Its not certainly Track nor Single Traction (to some extent) & definitely not Electrification which impact train schedule but congestion @ BSB/LKO Entrance: Its just like DND Flyway gets stretched into Ashram Entrance...After rocking fly-speed, u start crawling!!
U keep PBH/SLN Route complete double, but Utratia-Dilkusha too gonna remain Double only along with Dilkusha-LKO...how triple traffic can b adjusted as in same run flow, negotiating traffic akin 2 double & 1 single track...till this dont get resolved, train may cover in between BSB-LKO in 4 hrs...bt BSB-LKO may remain 5-6 hrs journey!!