Most commercial LiDAR trucks are accurate down to millimeters in relative terms and centimeters in absolute position terms. The equipment has been certified by approved surveying bodies, and there are official records as to that specific piece of collection equipment’s accuracy and precision.

If any autonomous car company could deliver data to that standard then it would be valuable. But to my knowledge none of them can, because the accuracy of measurement systems for surveying roads at motion are so specialized and expensive.

When I was there, it was a combination of (1) downwards facing line lasers measuring distance + reflectivity, (which was viewed as a greyscale image, around 4k pixels == width of a lane iirc) and (2) forward facing cameras for tagging assets like signs, plus (3) velodyne lidars for much coarser 3D point cloud (including measuring bridge heights). The scanning worked up to a bit under 70 mph, which was impressive to me, particularly that first part of the sensor package.