I saw a feature about Mercedes-Benz collision avoidance vision systems research on the Telly here in Germany where I am at the moment.
This particular project uses two cameras to create stereo vision. Comparing the two images is used to detect pixels that represent motion that could be hazardous to the vehicles current path.
Unfortunately, the clip above that I found on youtube doesn't have any explanatory voice-over, but appears to be the press-release footage. Still, if you have enough patience to watch the video, keep an eye out for the display inside the car which shows the calculated threat motion vectors
More about this, I do not know, but I thought it would be interesting for those looking at see-and-avoid systems for UAVs and the like
edit: just found this addional footage which shows the developer Uwe Franke describing the system in a little more detail - German and English sections follow each other
another little bit from Dr Stefan Gehring