In jrwalker-projects/farsfunctions: Read, summarize and map US traffic accident (FARS) data

library(knitr)
library(farsfunctions)

Functions for processing US traffic accident data

The farsfunctions package assists in reading and summarizing of US Department of Transportation data compiled by the National Highway Traffic Safety Administration (NHTSA) provided in the Fatality Analysis Reporting System (FARS). See the references section below for access to data, data descriptions and much more about FARS.

Package installation

The latest version of the farsfunctions package is installed from GitHub as shown here:

#Can skip this line if devtools is already installed
install.packages("devtools")

library(devtools)
install_github("jrwalker-projects/farsfunctions") #installs the package
library(farsfunctions) #loads package into R

Accident data files

knitr::opts_knit$set(root.dir = system.file("extdata",package="farsfunctions")) #sets knitr wd to package inst/extdata

The farsfunctions package works with accident files in the current working directory. Names of the files are expected to be of the form 'accident_YYYY.csv.bz2' where YYYY is the year of the file so specifically 'accident_2015.csv.bz2' for the 2015 accident file. If the files are not found, are not .csv files a message is returned. The files used in this vignette are:

dir()

Using the farsfunctions

Reading accident files for a set of years

The function make_file_name creates a file name string using a year provided so this can be combined with the function fars_read to unzip and read the csv file returning accident data as a tibble data frame, for example

accidents2016 <- fars_read(make_filename(2016)) #reads accident_2016.csv.bz2

kable(head(accidents2016[,1:9]))

Summarizing accidents

fars_read_years can read multiple years of accident files returning a list of accidents by year and month. The function fars_summarize_years calls fars_read_years to acquire such a list and summarize accident counts in a table by year and month:

my_summary <- fars_summarize_years(2015:2016)

kable(my_summary)

Plot a map of accident locations for a US state in a given year

The fars_map_state function plots a map of a requested US state placing a dot at locations of accidents in that state for a given year. For a list of state codes see the reference sections below. To produce a map for the US state of Alabama (state code 1) in the 2016 the call looks like

fars_map_state(1, 2016) #map Alabama accident locations for 2016

References

To download FARS For file downloads and more information on FARS data see the FARS website:

as of October 2017 see the latest manual on FARS data

or see the current available documents NCSA publications

FARS State Codes

At the time this vignette is written the following state codes are in use. To be sure check the latest manual.

states <- data.frame(StateCode=c(1:53), StateName=c('Alabama','Alaska','Arizona','Arkansas','California','Colorado','Connecticut','Delaware','District of Columbia','Florida','Georgia','Hawaii','Idaho','Illinois','Indiana','Iowa','Kansas','Kentucky','Louisiana','Maine','Maryland','Massachusetts','Michigan','Minnesota','Mississippi','Missouri','Montana','Nebraska','Nevada','New Hampshire','New Jersey','New Mexico','New York','North Carolina','North Dakota','Ohio','Oklahoma','Oregon','Pennsylvania','Puerto Rico','Rhode Island','South Carolina','South Dakota','Tennessee','Texas','Utah','Vermont','Virgin Islands (since 2004)','Virginia','Washington','West Virgina','Wisconsin','Wyoming')
)

kable(states)

Acknowledgements

None of the code for the R functions in this package was written by me. They were provided by person(s) unknown as part of the Coursera learning platform as part of the Johns-Hopkins course Building R Packages. My role as part of the coursework is to document the functions, create an R package and show that the package can be built and deployed. All of the code, documentation and packaging is available on GitHub at the location shown in the Installation section above.

jrwalker-projects/farsfunctions documentation built on May 29, 2019, 1:50 a.m.