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Download CRSS data files as zipped CSV or SAS files

Source: R/get_crss_zip.R
get_crss_zip.Rd

The Crash Report Sampling System (CRSS) is a national sample of police-reported motor vehicle crashes of all severities, from minor property damage to fatal crashes, and replaced the General Estimates System (GES) in 2016. This function is similar to get_fars_zip() to download CRSS files directly from the NHTSA downloads site. If read is TRUE, the function returns a list containing data frames for each table available in the selected year.

Usage

get_crss_zip(
  year = getOption("crashapi.year", 2024),
  format = "csv",
  path = NULL,
  aux = FALSE,
  read = TRUE,
  geometry = FALSE,
  overwrite = FALSE,
  keep_files = FALSE,
  var_labels = c("attribute", "none")
)

Arguments

year

One or more years of data from 2016 to 2024. Each year is downloaded separately and, if read = TRUE, returned as a list named by year. Defaults to getOption("crashapi.year", 2024).

format

Format of zipped data tables ('csv' or 'sas'). Default: 'csv'. read = TRUE and geometry = TRUE are only supported if format is "csv".

path

Directory for downloaded and cached files. If NULL (default), uses getOption("crashapi.cache_dir") or the user cache directory from tools::R_user_dir("crashapi", "cache").

aux

If TRUE, download auxiliary CRSS datasets.

read

If TRUE (default), read the cached parquet files into a list of tables with each list item corresponding to one data file.

geometry

Not supported for CRSS data, which does not include coordinates. If TRUE, a warning is shown and the accident table is returned as a data frame.

overwrite

If TRUE, download the data and replace any cached files. Default: FALSE

keep_files

If TRUE, keep the downloaded zip file and the extracted CSV files in the cache folder. Default: FALSE

var_labels

How to add variable labels: "attribute" (default) adds a "label" attribute to each column with a matching variable in fars_vars_labels and "none" doesn't add variable labels. Labels are taken from the FARS Analytical User's Manual so variables only used in CRSS are not labelled.

Value

If read = TRUE, a list of data frames with one item for each table (with the accident table converted to an sf object if geometry = TRUE). If read = FALSE, the cached parquet file paths named by table (or the zip file path if format = "sas") invisibly. If more than one year is provided, returns a list named by year.

Details

CRSS is a sample, so national estimates should use the sampling weight (WEIGHT) and survey design variables (e.g. PSU_VAR and PSUSTRAT) as described in the CRSS Analytical User's Manual. CRSS data does not include crash locations beyond broad geographic categories (e.g. REGION and URBANICITY).

Zipped CSV files are converted to parquet files and cached in a folder named after the zip file within path (by default, the user cache directory from tools::R_user_dir()), and the zip and CSV files are removed unless keep_files = TRUE. Later calls read the cached parquet files without downloading the data again unless overwrite = TRUE.