Interpreting the data
What these data tell us:
- These data tell us the number of fatal traffic crashes and the total number of traffic fatalities per county per year.
- Fatal traffic crashes are broken down by driver characteristics, road characteristics, date and time, vehicle miles traveled, and county demographics
What these data do not tell us:
- All variables that may be impacting fatal traffic crashes
- That certain individual or community characteristics are the strict cause of fatal traffic crashes
Numerator/Denominator Information
Event data
- Number of fatal traffic crashes, involving some sort of motor vehicle (car, truck, motorcycle, etc.)
- Number of total traffic fatalities, pedestrian fatalities, bicyclist fatalities
- Number of drivers involved in all fatal traffic fatalities (for some driver characteristics)
Denominator data
- In some cases, the total number of fatal traffic crashes (ex: x amount of crashes occurred in the daytime out of Y number of total fatal traffic crashes)
Limitations
Crashes that occur on roads that are county lines may be misidentified to the correct county where the crash occurred. Yearly Data for Vehicles Miles Traveled (VMT) is inconsistent and only relies on 2019 (the most recent year of data). For some crashes, variables of interest are not reported thus certain estimates may be under or overestimated.
Dataset Information
Data on fatal traffic crashes come from the Fatality Analysis Reporting System (FARS) from the National Highway Traffic Safety Administration. Vehicle Miles Traveled per county is estimated by multiplying the annual average daily traffic (AADT) by the length of the road. Demographic data was taken from the American Community Survey from the US Census Bureau.