It seems to me that both travel time and accidents are measured in human life minutes, and so if you count time spent driving as not living (or just half-living) then you could determine the speed limits that lead to most time spent alive, without bringing in any equivalence between human lives and dollars.
There are a couple of confounding factors, though. In the US, speed limits were briefly at 55 mph, which was a terrible idea, and increasing the speed limits to 65-75 mph resulted in no significant change in traffic fatalities, mostly because they didn’t result in many changes in driving habits. (The 85th percentile speed- what traffic engineers recommend you drive at- was often 15-20 mph above the speed limit in the 55 mph days. Now it’s about the same, but only ~5 mph above the limit.) In some states, speed limit increases on safer interstates (while maintaining lower speed limits on more dangerous rural highways) led to improved safety, as more drivers used the interstates and more policing resources were spent on the dangerous roads (as police enforcement of traffic laws is primarily done for revenue generation).
Another is flow. Excessive speed is involved in about a third of accidents, but driver inattention is involved in pretty much every accident. I would much rather be driving 90 mph and be fully engaged than be driving 60 mph and be zoning out, and so an autobahn-style policy of “drive whatever speed is appropriate for you” may be best for well-engineered and well-maintained roads (though there are other tradeoffs involved there).
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.
It seems to me that both travel time and accidents are measured in human life minutes, and so if you count time spent driving as not living (or just half-living) then you could determine the speed limits that lead to most time spent alive, without bringing in any equivalence between human lives and dollars.
There are a couple of confounding factors, though. In the US, speed limits were briefly at 55 mph, which was a terrible idea, and increasing the speed limits to 65-75 mph resulted in no significant change in traffic fatalities, mostly because they didn’t result in many changes in driving habits. (The 85th percentile speed- what traffic engineers recommend you drive at- was often 15-20 mph above the speed limit in the 55 mph days. Now it’s about the same, but only ~5 mph above the limit.) In some states, speed limit increases on safer interstates (while maintaining lower speed limits on more dangerous rural highways) led to improved safety, as more drivers used the interstates and more policing resources were spent on the dangerous roads (as police enforcement of traffic laws is primarily done for revenue generation).
Another is flow. Excessive speed is involved in about a third of accidents, but driver inattention is involved in pretty much every accident. I would much rather be driving 90 mph and be fully engaged than be driving 60 mph and be zoning out, and so an autobahn-style policy of “drive whatever speed is appropriate for you” may be best for well-engineered and well-maintained roads (though there are other tradeoffs involved there).
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.