Sigh... this issue is so bloody simple to resolve.
1. Default to a default set of morals, which include a reasonable (but not excessive) degree of self-sacrifice - based around the sort of decisions a "typical" driver would make.
That sounds anything but simple.
Yes it is, it's all about reusing existing quality code, such as face recognition libraries and Wisconsin's Prison-Sentencing Algorithm. I wonder how many repeat offenders there are in 10 average pedestrians.