Driving/Data
Baseline rates (verbatim; used directly in models)
The following U.S. national rates are taken verbatim from authoritative sources and are **not** converted here. Conversions to per-miles exposure are performed only inside the RiskModel calculations below.
- Fatalities: **1.26 deaths per 100 million vehicle miles traveled (VMT)** in 2023 (national estimate).
* NHTSA 2023 Traffic Fatalities Estimates * IIHS: Fatality statistics
- Injuries: **75 injuries per 100 million VMT** in 2022 (police-reported injuries, national estimate).
* NHTSA: Traffic Safety Facts 2022
Distance Options
| Distance choice | Miles |
|---|---|
|
100 miles |
100 |
|
1,000 miles |
1000 |
|
100,000 miles |
100000 |
These rows provide user-friendly exposure choices. The RiskModels convert the per-100M-VMT base rates into expected counts for the chosen miles.
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: in 2022, ~53.9% of fatalities and ~32.9% of injury crashes occurred during roughly ~25% of VMT (nighttime). Using exposure-adjusted ratios yields ≈3.56× (fatalities) and ≈1.47× (injuries).
- Night/day crash distribution and injuries: NHTSA 2022
- Background on time-of-day involvement: NHTSA
- Exposure assumption (≈25% of VMT at night): FHWA Lighting Guidance
- Supplemental analysis: University of Michigan per-mile risk
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 |
Seat belts reduce fatal injury risk by ~45% in cars and ~60% in light trucks; moderate-to-critical injury by ~50% in cars and ~65% in light trucks. The multipliers above are the inverse of those reductions (i.e., increased risk when not wearing a belt).
- Effectiveness summary: IIHS: Seat belts
- Technical background: NHTSA: Seat belt effectiveness
RiskModel: Driving/Data:fatality_model
Calculation: (1.26 / 100000000 * distance_miles) * time_fatality_multiplier * belt_fatality_multiplier
Content:
Your estimated chance of being in a fatal crash is {{One_In_X|{result}}}.
RiskModel: Driving/Data:injury_model
Calculation: (75 / 100000000 * distance_miles) * time_injury_multiplier * belt_injury_multiplier
Content:
Your estimated chance of being injured in a crash is {{One_In_X|{result}}}.
Note on uncertainty: These are national averages and approximate modifiers. Actual risks vary by state, roadway type (urban/rural), weather, vehicle, driver demographics, and year-to-year changes. Modifiers are population-level and not individual predictions.
Mostly generated by GPT-5 Thinking