A machine routing and planning system for mobile machines at a work site includes a plurality of haul trucks, a loading machine, and a controller. The controller is configured to determine an initial effective capacity based on an initial amount of carryback material, and generate an initial material movement plan based upon the number of machines, the capacity of the loading machine and the initial effective capacity of each haul truck. The controller is further configured to determine a modified effective capacity for each haul truck based on a current amount of carryback material, and generate a modified material movement plan based upon the number of machines, the capacity of each loading machine, and the modified effective capacity for each haul truck.