Various embodiments include methods, devices, and robotic vehicle processing devices implementing such methods for automatically adjusting the minimum distance that a robotic vehicle is permitted to approach an object by a collision avoidance system (the “proximity threshold”) to compensate for unpredictability in environmental or other conditions that may compromise control or navigation of the robotic vehicle, and/or to accommodate movement unpredictability of the object. Some embodiments enable dynamic adjustments to the proximity threshold to compensate for changes in environmental and other conditions. Some embodiments include path planning that takes into account unpredictability in environmental or other conditions plus movement unpredictability of objects in the environment.