receiving, from a primary controller, information comprising an active trajectory of an AV, the active trajectory being a path that the AV intends to follow for a planning horizon;

using the active trajectory to identify one or more regions in an environment of the AV, the one or more regions comprising the following: a fallback monitoring region (FMR) and an active monitoring region (AMR);

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; and

transmitting the one or more instructions to an AV platform (AVP) for execution,

wherein the FMR corresponds to a first length from a first current position of the AV to a first stopping point and the first stopping point is a point on the active trajectory that is reached by the AV at a first allowed deceleration rate when the collision mitigation action is executed;

wherein the AMR corresponds to a second length from a second current position of the AV to a second stopping point and the second stopping point is a point on the active trajectory that is reached by the AV at a second allowed deceleration rate when the collision mitigation action is executed; and

wherein the first length is greater than the second length.