> Its only purpose is to pool risk.

Precisely - there is a rational case for insurance despite your analysis.

The fact that cars have, on average, become heavier lately is at most a cherry-picked second-order effect that is far from sufficient to refute either what I wrote in my previous post, or in my original post in this thread. Despite your analysis, it is plausible, and IMHO extremely likely, that the same forces that have led to the improved situation since Winterbottom v. Wright will continue to improve the situation for pedestrians and other motorists, as they have in the past.