जिंदगी में शादी के अलावा ट्रेन में RAC ही एक ऐसी स्थिति है,जिसमें दो अजनबी साथ निभाने को मजबूर होते है। - Junaid

If you see the distance KM wise,
Route 1
BGP-KIUL-GAYA = 228 RKM + GAYA-GMO = 170 RKM + GMO-RNC = 39 RKM + RNC-BSP = 477 RKM TOTAL = 914 RKM
Route 2
BGP-DUMK-RPH...
more...

= 180 RKM + RPH-ASN = 160 RKM + ASN-PRR-ROU = 256 RKM + ROU-BSP = 305 RKM TOTAL 901 RKM
So the difference is just 13 RKM
Now, as both the routes are almost same in length, the other factors should be considered like reversals, providing connectivity (first time), earning, track mps, etc.