That's not an assumption but a reliance for IFR. You clear your path with air traffic control before engaging the autopilot. Collision-avoidance is not part of

That's not an assumption but a reliance for IFR. You clear your path with air traffic control before engaging the autopilot. Collision-avoidance is not part of the autopilot in aircraft. And the pilot decides on the path. In conclusion there are few similarities between an aircraft pilot and driving assistance in cars.