The speed up of BAK loop trains (b/w JRLE-BDC) had been done till last TAAG'23 which significantly reduced the journey time.
The remaining section (JRLE-NFK, but only 7km b/w AHN-SPLE) was blocked due to this new Ahiran rail bridge under doubling project. Now IR should remove the slack time between JRLE-SPLE.
For...
more... example, UP Hate Bazare use to wait around 55-60 mins at JRLE due to this. Similarly UP Intercity (via AZ) use to wait around 15-20 mins before time at JRLE and there are many like UP Nabadwip Balurghat, UP Kamrup, UP Radhikapur etc.
So as you understand most of them are UP bound trains waiting at JRLE for crossing JRLE-SPLE section blocked by single Ahiran Rail Bridge.