This feels like we’re missing a dimension or threeve, the one that comes to mind immediately would be whether or not the deceased driver was at fault for the incident.
But can't you account for 'type of car', 'type of road', 'commute length' as direct variables pretty easily without dipping into social/economic backgrounds?
Although it certainly isn't "easy" to measure all of this directly; there are thousands of that constitute the type of driving scenario that someone might engage in. Even just "type of road" isn't a single thing, it's hundreds of things.