Driving/Data: Difference between revisions

Revision as of 23:15, 31 August 2025

Distance & Baseline Rates

Distance choice	Miles	Thousands of miles (multiplier)	Baseline fatalities per 1,000 miles	Baseline serious injuries per 1,000 miles
100 miles	100	0.1	0.0126	0.75
1,000 miles	1000	1	0.0126	0.75
100,000 miles	100000	100	0.0126	0.75

Baseline fatality rate (2023): **1.26 deaths per 100 million VMT** → **0.0126 per 1,000 miles**. Baseline injury rate (2022): **75 injuries per 100 million VMT** → **0.75 per 1,000 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 in night hours while ~25% of VMT occurs at night, yielding ≈3.56× (fatalities) and ≈1.47× (injuries).

NHTSA: 2022 crash statistics
NHTSA: Time of day & crash involvement
Exposure assumption: ~25% of VMT at night (FHWA Lighting Guidance)

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. Multipliers above are the inverse of those reductions.

  RiskModel: Driving/Data:fatality_model
Calculation: base_fatalities_per_1000_miles * distance_thousand_miles * time_fatality_multiplier * belt_fatality_multiplier
    Content: 
Your estimated fatality risk for {distance_label} is about {result}.

  RiskModel: Driving/Data:injury_model
Calculation: base_injuries_per_1000_miles * distance_thousand_miles * time_injury_multiplier * belt_injury_multiplier
    Content: 
Your estimated serious injury risk for {distance_label} is about {result}.

Note on uncertainty: These values are national averages and should be seen as approximate indicators. Actual risks vary by roadway type (urban/rural), vehicle, weather, geography, and year. Multipliers are population-level and may not predict individual outcomes.

Generated by ChatGPT-5

@@ Line 1: / Line 1: @@
-'''Fatality Risk'''
+'''Distance & Baseline Rates'''
-<datatable2 table="fatality_risk" columns="distance_thousand_miles|fatalities_per_1000_miles">
+<datatable2 table="distance_options" columns="distance_label|distance_miles|distance_thousand_miles|base_fatalities_per_1000_miles|base_injuries_per_1000_miles">
 <head>
-!Distance (thousands of miles)
+!Distance choice
-!Fatalities per 1,000 miles
+!Miles
+!Thousands of miles (multiplier)
+!Baseline fatalities per 1,000 miles
+!Baseline serious injuries per 1,000 miles
 </head>
-|0.0126
+miles|100|0.1|0.0126|0.75
+,000 miles|1000|1|0.0126|0.75
+,000 miles|100000|100|0.0126|0.75
 </datatable2>
-This table is based on 2023 U.S. traffic data: about 1.26 fatalities per 100 million vehicle miles traveled (VMT), which equals 0.0126 fatalities per 1,000 miles.
+Baseline fatality rate (2023): **1.26 deaths per 100 million VMT** → **0.0126 per 1,000 miles**.
-* [https://www.iihs.org/research-areas/fatality-statistics/detail/state-by-state IIHS: Fatality statistics]
+Baseline injury rate (2022): **75 injuries per 100 million VMT** → **0.75 per 1,000 miles**.
 * [https://www.nhtsa.gov/press-releases/nhtsa-2023-traffic-fatalities-2024-estimates NHTSA 2023 Traffic Fatalities Estimates]
+* [https://www.iihs.org/research-areas/fatality-statistics/detail/state-by-state IIHS: Fatality statistics (rates per VMT)]
-'''Injury (Serious) Risk'''
+* [https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813560 NHTSA: Traffic Safety Facts 2022 (injury rates)]
-<datatable2 table="injury_risk" columns="distance_thousand_miles|injuries_per_1000_miles">
-<head>
-!Distance (thousands of miles)
-!Serious injuries per 1,000 miles
-</head>
-|0.75
-</datatable2>
-This is based on 2022 NHTSA estimates: about 75 injuries per 100 million VMT, which equals 0.75 injuries per 1,000 miles.
-* [https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813560 NHTSA: Traffic Safety Facts 2022]
 '''Time of Day (Modifier)'''
@@ Line 38: / Line 32: @@
 </datatable2>
-Per-mile risk is higher at night because more crashes happen during the ~25% of miles driven in darkness. In 2022, about 53.9% of fatalities and 32.9% of injury crashes occurred at night, leading to multipliers of ≈3.56× (fatalities) and ≈1.47× (injuries).
+Per-mile risk is higher at night: in 2022, ~53.9% of fatalities and ~32.9% of injury crashes occurred in night hours while ~25% of VMT occurs at night, yielding ≈3.56× (fatalities) and ≈1.47× (injuries).
 * [https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813560 NHTSA: 2022 crash statistics]
-* [https://crashstats.nhtsa.dot.gov/Api/Public/Publication/810637 NHTSA: Time of day and crash involvement]
+* [https://crashstats.nhtsa.dot.gov/Api/Public/Publication/810637 NHTSA: Time of day & crash involvement]
-* [https://deepblue.lib.umich.edu/bitstream/handle/2027.42/1007/83596.0001.001.pdf University of Michigan: Night vs. day crash risk analysis]
+* Exposure assumption: ~25% of VMT at night ([https://safety.fhwa.dot.gov/roadway_dept/night_visib/lighting_handbook/chap_3/chap3_2.cfm FHWA Lighting Guidance])
-* Exposure assumption: ~25% of vehicle miles traveled occur at night ([FHWA Lighting Guidance](https://safety.fhwa.dot.gov/roadway_dept/night_visib/lighting_handbook/chap_3/chap3_2.cfm))
 '''Seat-belt Usage (Modifier)'''
@@ Line 58: / Line 51: @@
 </datatable2>
-Multipliers reflect NHTSA/IIHS estimates:
+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. Multipliers above are the inverse of those reductions.
-- In cars, seat belts cut fatality risk by ~45% (→ not wearing = 1 ÷ 0.55 ≈ 1.82×) and serious injury risk by ~50% (→ 2.0×).
-- In light trucks, belts cut fatality risk ~60% (→ 2.5×) and injury ~65% (→ 2.857×).
 * [https://www.iihs.org/research-areas/seat-belts IIHS: Seat belts]
 * [https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/811160 NHTSA: Seat belt effectiveness]
@@ Line 66: / Line 57: @@
 ----
-<RiskModel name="fatality_model" calculation="fatalities_per_1000_miles * time_fatality_multiplier * belt_fatality_multiplier">
+<RiskModel name="fatality_model" calculation="base_fatalities_per_1000_miles * distance_thousand_miles * time_fatality_multiplier * belt_fatality_multiplier">
-Your estimated fatality risk per 1,000 miles is about {result}.
+Your estimated fatality risk for {distance_label} is about {result}.
 </RiskModel>
-<RiskModel name="injury_model" calculation="injuries_per_1000_miles * time_injury_multiplier * belt_injury_multiplier">
+<RiskModel name="injury_model" calculation="base_injuries_per_1000_miles * distance_thousand_miles * time_injury_multiplier * belt_injury_multiplier">
-Your estimated serious injury risk per 1,000 miles is about {result}.
+Your estimated serious injury risk for {distance_label} is about {result}.
 </RiskModel>
 ----
-''Note on uncertainty'': These values are national averages and should be seen as approximate indicators. Actual risks vary depending on geography, roadway type (urban vs. rural), vehicle type, weather conditions, driver demographics, and year-to-year fluctuations. Multipliers for night driving and seat-belt use are based on population-level data and may not precisely predict individual risk.
+''Note on uncertainty'': These values are national averages and should be seen as approximate indicators. Actual risks vary by roadway type (urban/rural), vehicle, weather, geography, and year. Multipliers are population-level and may not predict individual outcomes.
 Generated by [https://openai.com/ ChatGPT-5]