It bears repeating. When a car driver says, "I just didn't see him," he or she may be 100% correct. Not seeing a motorcycle rider, or bicycle rider, or pedestrian, is not always a case of negligence. They may in fact have not seen the rider because of the way our eyes and brains work, i.e., it's a physiological function. Read this article for a good explanation of why it happens. It was written by an RAF fighter pilot.
https://www.dropbox.com/s/elegi6k9am...Final.pdf?dl=1
Jack, contrary to your comment Idaho STAR found in a study of accidents from 2009-20013 that 67% of fatalities were caused by rider error. Here's a quote from this report, page 46.
https://www.nhtsa.gov/sites/nhtsa.do..._fy2017_ar.pdf
What these statistics and articles confirm is, as has been said in above posts, it is incumbent upon riders to practice defensive riding.