>Would LIDAR have helped, or would the presented surface area of the concrete block be too small to act upon?

from the beheading accident discussion couple years ago i remember that Tesla had radar in front. That incident back then happened supposedly because the radar was observing only low-height sector along the road surface. The concrete divider seems to be exactly the thing that the radar would see. LIDAR as well as stereo of course would see that divider easily. It seems at this point though that Tesla's autopilot is only something like single camera image recognition, probably still is or like a MobilEye.