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Old 11-03-2009, 07:20 PM   #1 (permalink)
Engineering first
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Join Date: Mar 2009
Location: Huntsville, AL
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14 i3-REx - '14 BMW i3-REx
Last 3: 45.67 mpg (US)

17 Prime Plus - '17 Toyota Prius Prime Plus
90 day: 58.25 mpg (US)
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Prius fatal accident rate

All of the details are here:

Prius Fatalities 2001-2007

The Prius fatality rate of 0.64 per 100 million miles is less than half of the NHTSA 1.37-1.51 fatalities per 100 million miles for the years 2001-2007. This is based upon the annual Prius sales from 2000-2007 minus an overly high estimate of 3% Prius lost per year; an annual usage of 15,000 miles per Prius per year; and 75 prorated deaths of the 124 fatalities from 111 fatal accidents including Prius and non-Prius vehicles. A more conservative accounting of Prius contributions, a count of Prius participation by accident, gives an even lower rate, 0.55 Prius fatalities per 100 million miles.
. . .
If a Prius and another car are engaged in a two-car accident, the Prius gets 50% of the credit. So initially, I just calculated the ratio of all Prius and non-Prius vehicles in accidents to prorate the deaths. This gave a prorated, 74 deaths due to the existence of the Prius in the accident. But then I noticed some accidents were just single car, Prius accidents.

I went back and recalculated the deaths per accident prorated by the Prius percentage. Much to my surprise, it came even lower, 0.55 Prius fatalities per 100 million miles.

The web page lists all Prius involved, fatal accidents from 2001-2007. It also shows how I calculated the number of Prius on the road from the annual Prius sales minus a worst case, 3% loss per year, and accounting for only half of the miles for a car sold in the first year of service. Thus our Prius skeptics have a problem, the facts and data are unkind to them.

Bob Wilson

2019 Std. Range Plus Model 3 - 134 MPG3 || 2014 BMW i3-REx - 117 MPGe, 39 MPG
JuiceBox 40 Pro (240 VAC, 40 A), KHONS portable (120-240 VAC, 12-32 A)
Retired engineer, Huntsville, AL (five times AutoPilot saved.)
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