System includes a controller comprising one or more processors configured to generate alertness requests to an operator of a vehicle system during a trip. The alertness requests are generated according to a determined routine. The controller is further configured to receive reactive inputs from the operator that are responsive to the alertness requests. The controller is further configured to determine whether the trip includes a permissible route segment for suspending the determined routine. The permissible route segment has a route characteristic of one or both of: a reduced likelihood of operator-required events occurring or a predicted workload for the operator that is less than a defined workload threshold.