Most of them are at the base of structures like signs and trees. In a few places it looks like the Z projection is overlaid onto the video with the wrong perspective, so it's hard to tell. My guess is that they are generic stationary object recognition tags that serve as hints about what isn't part of the road.
They seem to be points related to those shown as white road outline on right bottom quarter, also when a car drives across view at 0:24 it is marked by blue dots too, so it must be radar data for road boundaries and physical obstacles (like building wall at 0:15).
