Rdp wont be of much use for Lalgola section. Basically this Nasipur bridge will connect 3 major station with mainland Bengal - Ranaghat, Krishnanagar and Baharampur. Among these, Ranaghat and Krishnanagar mainly requires train for North Bengal, specifically Siliguri. And Baharampur needs a intercity train for Malda along with a train for Siliguri. So diverting Rdp won't be of much use because the demand is mainly for Siliguri and Rdp dont even touch Siliguri on its route.