nycbuildxwalks

nycbuildxwalks downloads official New York City geographic boundary data and generates comprehensive crosswalk tables showing how administrative and spatial boundaries overlap. It produces both wide-format and long-format CSV crosswalks with intersection area and percentage calculations.

This is an R port of the Python NYC geography crosswalks tool by Nathan Storey at MODA-NYC, which builds on earlier work by BetaNYC.

Supported geographies

id	dataset_name
cd	Community Districts
pp	Police Precincts
dsny	Sanitation Districts
fb	Fire Battalions
sd	School Districts
hc	Health Center Districts
cc	City Council Districts
nycongress	Congressional Districts
sa	State Assembly Districts
ss	State Senate Districts
bid	Business Improvement Districts
nta	Neighborhood Tabulation Areas
zipcode	Modified ZIP Code Tabulation Areas
hd	Historic Districts
ibz	Industrial Business Zones

Installation

You can install the development version of nycbuildxwalks from GitHub with:

# install.packages("pak")
pak::pak("kjhealy/nycbuildxwalks")

Alternatively, install this package from my r-universe:

install.packages(
  "nycbuildxwalks",
  repos = c("https://kjhealy.r-universe.dev", "https://cloud.r-project.org")
)

Including https://cloud.r-project.org ensures dependencies on CRAN are resolved automatically.

Usage

The main entry point is make_run(), which orchestrates the full pipeline:

library(nycbuildxwalks)

# Full run: download boundaries and build all crosswalks
run_dir <- make_run()

# With ZIP archives
run_dir <- make_run(zip_artifacts = TRUE)

# Test with limited features
run_dir <- make_run(max_primaries = 2, primary_only = c("cd", "pp"))

You can also run individual steps:

# Step 1: Download and combine boundaries
run_dir <- download_all_boundaries()

# Step 2: Build crosswalks from existing boundaries
build_crosswalks(
  boundaries_path = file.path(run_dir, "all_boundaries.geojson"),
  run_dir = run_dir
)

Methodology

• ZIP codes are MODZCTAs: The zipcode layer uses DOHMH MODZCTA polygons. Results may differ from USPS ZIP definitions.

• Geometry validity: After combining inputs, invalid geometries are repaired with sf::st_make_valid().

• Intersection de-noising: A small negative buffer (-50 ft by default) is applied during intersection to reduce line-touching artifacts. Candidates are not filtered by this buffer. After intersection, a minimum area threshold (100 sq ft) suppresses noise.

• Multipart primaries: Primary features are dissolved by name so multipart geometries are treated as a single unit.

• Area calculations: All spatial operations use EPSG:2263 (NY State Plane, feet) for accurate area computation.

Outputs

Each run produces a timestamped directory under outputs/ containing:

• all_boundaries.geojson — combined boundary file
• run_meta.json — source URLs, cycle resolutions, git SHA
• longform/ — one CSV per primary geography with pairwise intersection details
• wide/ — one CSV per primary geography with semicolon-separated overlapping feature names
• crosswalks_meta.json — buffer, thresholds, and IDs used

Acknowledgements

This package is based on the Python tool by Nathan Storey at MODA-NYC, which builds on the concepts and data aggregation methods originally implemented in the BetaNYC NYC Boundaries Map repository.

Hexlogo Photo: Detail from “Brooklyn Paving 5-25-16”, NYC DOT.