[xnx]

In addition to detecting the object, Waymo has to make some determination about the material. Rigid heavy metal = slam on the brakes and/or swerve. Piece of tire or plastic bag = OK to run over if swerving or hitting the brakes would be more dangerous. Really hard problem that they're concerned about getting right before they open up highway driving.

[ModernMech]

LiDAR is also good for that because you can measure light remission and figure out how much of the LiDAR energy the material absorbed. Different materials have different remission properties which can be used to discriminate. Which is a compounding advantage because we tend to paint road line markers with highly reflective paints. This makes line markers blindly obvious to a LIDAR.