FARS2024NationalAuxiliarySAS.zip

File Identity

FARS2024NationalAuxiliarySAS.zip is the 2024 national auxiliary SAS package for NHTSA's Fatality Analysis Reporting System. FARS is a census of fatal motor vehicle traffic crashes in the United States. The auxiliary SAS package is the SAS transport format edition of the supplemental analytical tables — chiefly multiple imputation (MI) data files — that extend the core crash, vehicle, and person records found in FARS2024NationalSAS.zip.^1,2,3

Researchers who work natively in SAS use this package when they need nationally representative estimates for variables that the raw FARS records frequently code as unknown. The SAS transport format (.xpt) allows the files to be read directly by SAS LIBNAME with the XPORT engine, or by compatible open-source readers such as the R haven package or Python pyreadstat.^1,4

What the Package Contains

The auxiliary SAS ZIP contains SAS transport (.xpt) files that mirror the tables in the auxiliary CSV package. The core content is the set of Multiple Imputation (MI) files NHTSA generates to address systematic data gaps in raw crash reports. Each MI file corresponds to a level of the FARS hierarchy — accident, driver/accident, and person — and provides multiply-imputed estimates alongside the original coded values.^3,4

SAS Format vs. CSV Format

NHTSA publishes each FARS annual package in two parallel formats: CSV (comma-separated text) and SAS transport (.xpt). The SAS auxiliary package and the CSV auxiliary package contain the same imputation data — they differ only in encoding.^2,3,5

How Daily Driver Advocate Uses It

Daily Driver Advocate documents the NHTSA FARS auxiliary SAS package as a reference for researchers who work in SAS-based analysis pipelines. The site's own statistical processing uses the CSV packages, but the SAS auxiliary package is the format NHTSA's own analysts typically use and is referenced in the FARS Analytical User's Manual as the authoritative source for imputed-variable analysis.^1,3,5,6

Common Research Uses

The auxiliary SAS package is most useful when a researcher works within a SAS-native pipeline and needs nationally representative estimates for FARS variables with high unknown rates — primarily BAC and travel speed — without converting the data to CSV first.^1,4

Important Limitations

• This package is supplemental — it must be used alongside FARS2024NationalSAS.zip, not as a standalone crash dataset.
• The SAS transport (.xpt) format requires SAS software or a compatible reader such as the SAS XPORT engine in R (haven package) or Python (pyreadstat). It is not a plain CSV or spreadsheet file.
• Multiple imputation tables do not assign a single definitive value; they produce multiple plausible estimates intended for use with SAS PROC MIANALYZE or equivalent statistical pooling procedures.
• Imputed values are statistical estimates generated by NHTSA models, not confirmed measurements. They are appropriate for aggregate national estimates, not for case-level fact-finding.
• FARS covers fatal crashes only. Neither the main nor the auxiliary SAS package records injury-only or property-damage crashes.
• A crash must involve a motor vehicle on a public trafficway and result in a death within 30 days to be included in any FARS file.
• Consult the FARS Analytical User's Manual (linked in the primary source directory) for the exact variable definitions, coding notes, and imputation methodology used in each auxiliary table.

Suggested Citation

For the raw dataset, cite NHTSA as the issuing agency and link to the official file. When citing this explanatory card, cite Daily Driver Advocate as the independent research project that documented the source.