Abstract: Systems and methods for complementary control of an autonomous vehicle (AV) are disclosed. The methods include receiving information comprising an active trajectory of an AV that the AV intends to following for a planning horizon. The methods also include using the active trajectory to identify one or more regions in an environment of the AV such as a fallback monitoring region (FMR) and an active monitoring region (AMR), and generating one or more instructions for causing the AV to execute a collision mitigation action in response to an object being detected within the AMR. The methods further include transmitting the one or more instructions to an AV platform (AVP) for execution.