primary_secondary_roads {tigris}

Download a primary & secondary roads shapefile into R

Description

From the Census Bureau: "Primary roads are generally divided, limited-access highways within the Federal interstate highway system or under state management. These highways are distinguished by the presence of interchanges and are accessible by ramps and may include some toll highways. Secondary roads are main arteries, usually in the U.S. highway, state highway, or county highway system. These roads have one or more lanes of traffic in each direction, may or may not be divided, and usually have at-grade intersections with many other roads and driveways.

Usage

primary_secondary_roads(state, year = NULL, ...)

Arguments

state

The two-digit FIPS code of the state of the county you'd like to download the roads for. Can also be state name or abbreviation (case-insensitive).

year

the data year; defaults to 2022

...

arguments to be passed to internal function load_tiger, which is not exported. See Additional Arguments.

Value

an sf object with columns

• LINEARID: a unique line feature identifier (source)

• FULLNAME: display name (source)

• RTTYP: describes the types of roads used (source). Possible values are:

  • "C": county

  • "I": interstate

  • "M": common name

  • "O": other

  • "S": state regonized

  • "U": U.S.

• MTFCC: 5-digit geographic code assignment (see annual assignments)

Additional Arguments

Additional arguments that can be passed in ... are:

• class Desired class of return object: "sf" (the default) or "sp". sp classes should be considered deprecated as of tigris version 2.0, but legacy support is still available.

• progress_bar If set to FALSE, do not display download progress bar (helpful for R Markdown documents). Defaults to TRUE.

• keep_zipped_shapefile If set to TRUE, do not delete zipped shapefile (stored in temporary directory or TIGRIS_CACHE_DIR depending on the configuration of global option "tigris_use_cache"). Defaults to FALSE.

• refresh Whether to re-download cached shapefiles (TRUE or FALSE) . The default is either FALSE or the value of global option "tigris_refresh" if it is set. Specifying this argument will override the behavior set in "tigris_refresh" global option.

• filter_by Geometry used to filter the output returned by the function. Can be an sf object, an object of class bbox, or a length-4 vector of format c(xmin, ymin, xmax, ymax) that can be converted to a bbox. Geometries that intersect the input to filter_by will be returned.

See Also

https://www2.census.gov/geo/pdfs/maps-data/data/tiger/tgrshp2020/TGRSHP2020_TechDoc.pdf

Other transportation functions: address_ranges(), primary_roads(), rails(), roads()

Examples

## Not run: 
library(tigris)

rds <- primary_secondary_roads()

plot(rds$geometry)


## End(Not run)