Driving/Data

Fatality Risk

Distance (thousands of miles)	Fatalities per 1,000 miles
1	0.0126

This table is based on 2023 NHTSA data: about 1.26 fatalities per 100 million vehicle miles traveled (VMT) in the U.S., which equals 0.0126 fatalities per 1,000 miles.

• IIHS: Fatality statistics
• NHTSA 2023 Traffic Fatalities Estimates

Injury (Serious) Risk

Distance (thousands of miles)	Serious injuries per 1,000 miles
1	0.75

This is based on 2022 NHTSA estimates: about 75 injuries per 100 million VMT, which equals 0.75 injuries per 1,000 miles.

• NHTSA: Traffic Safety Facts 2022

Time of Day (Modifier)

Time of day	Fatality risk multiplier	Injury risk multiplier
Day	1.0	1.0
Night	3.56	1.47

Per-mile risk is higher at night because more crashes happen during the ~25% of miles driven in darkness. In 2022, ~53.9% of fatalities and ~32.9% of injury crashes occurred at night, leading to per-mile multipliers of ≈3.56× (fatalities) and ≈1.47× (injuries).

• NHTSA: Time of day and crash involvement
• NHTSA: 2022 crash statistics
• University of Michigan, Per-mile risk analysis

Seat-belt Usage (Modifier)

Seat-belt usage	Fatality risk multiplier	Injury risk multiplier
Worn (car)	1.0	1.0
Not worn (car)	1.82	2.0
Worn (SUV/van/truck)	1.0	1.0
Not worn (SUV/van/truck)	2.5	2.857

Multipliers reflect NHTSA/IIHS estimates: - In cars, seat belts cut fatality risk by ~45% (→ not wearing = 1 ÷ 0.55 ≈ 1.82×) and injury risk by ~50% (→ 2.0×). - In light trucks, belts cut fatality risk ~60% (→ 2.5×) and injury ~65% (→ 2.857×).

• IIHS: Seat belts
• NHTSA: Seat belt effectiveness

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  RiskModel: Driving/Data:fatality_model
Calculation: fatalities_per_1000_miles * fatality_multiplier * belt_fatality_multiplier
    Content: 
Your estimated fatality risk per 1,000 miles is about {result}.

  RiskModel: Driving/Data:injury_model
Calculation: injuries_per_1000_miles * injury_multiplier * belt_injury_multiplier
    Content: 
Your estimated serious injury risk per 1,000 miles is about {result}.

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