Aside from resolution, another reason suggested is to avoid slamming on the breaks in the middle of a highway for false-positives. https://www.wired.com/story/

Aside from resolution, another reason suggested is to avoid slamming on the breaks in the middle of a highway for false-positives. https://www.wired.com/story/tesla-autopilot-why-crash-radar/ https://www.wired.com/story/tesla-autopilot-why-crash-radar/