CNN just published a report "Higher speed limits mean more deaths" ( http://www.cnn.com/US/9901/14/speeding.deaths.ap/ ) from the studies conducted by National Highway Traffic Safety Administration and insurance companies.
The studies conclude that in the states that raised speed limits, highway death rates increased by 12 to 15%.
General statistics: "people drove a little more than 2.5 trillion miles in 1997, and the death rate was 1.6 per 100 million miles traveled - an all-time low."
I am always suspicious reading statistics from agencies that are financially interested in the results - in this case, collecting speeding fines and carrying the price of insurance.
In this case, they seem to forget to take into account that some of the victims of deadly crashes would, at a slightly lower speed, get "only" severely maimed, or that there may be something special about the states that increased the speed limit - like, increasingly congested traffic, or that some people may now choose to drive through a state that has higher speed limits, etc.
But I would like to suggest a different statistic.
Let's assume that the death rate rises linearly with speed limit
(looks like the case now). So 10% increase in speed limit would
raise death rates by 0.16 per 100 million miles traveled.
So on average, a person would lose half of their life's worth of
waking time per each incident = 35 years * 365 days * 16 hours * 0.16
= roughly, 33,000 hours per 100 million miles traveled.
But then, the same speed increase would save people time for productive
and pleasant activities, with the savings:
The only problem, they don't save money to insurance companies.