I'll be very surprised if Konkvistador posted this to talk about the speed limits.
Mitchell was mocking the position that human lives and dollars can be interchanged. I believe in that position, but the actual suggestion made- the cost/benefit analysis- can be done without holding that position, and I figured it was better to describe that at length rather than just say Mitchell was strawmanning.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.