A quick check of Google Maps using Street View shows the speed limit on SR 405 is 45 miles per hour. I would expect no casualties at that speed. I started searching using the pickup truck's prior intersection at Grissom Parkway. I hope someone else checks this to verify.
I think the truck driver's record needs to be reviewed, including phone and vehicle data recorder if available.
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View my fuel log 2015 Mirage ES 1.2 manual: 49.6 mpg (US) ... 21.1 km/L ... 4.7 L/100 km ... 59.5 mpg (Imp)