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accessibility

ANALYTICS
Velocity0.0

Transport Accessibility Measures

github.com/ipea/accessibility ↗

An urban accessibility toolkit that grew into a distributional-equity toolkit.

r-packageurban-mobilityaccessibilityspatial-analysisinequality-metrics
◆Current state
accessibility, from IPEA's geo team, computes how reachable opportunities are given a travel matrix and land use data. Since the 1.0.0 rebuild it has widened well past reachability metrics: 1.1.0 added inequality and poverty estimation alongside spatial availability and balancing cost, 1.2.0 added the concentration index and Theil T, and 1.3.0 let spatial_availability() return results per origin-destination pair with the underlying balancing factors exposed.
◆Where it's heading
The package is moving from measuring access to measuring who is left out, and doing it by adding metrics rather than reworking the core. A second, quieter theme is generality — nearly every parameter that once took a single value now accepts vectors or lists, so users can sweep across cutoffs and decay specifications in one call. The decay family keeps growing, most recently with a logistic form.
◆Prediction
Further inequality or decay functions are the most likely next addition, given that both families have grown steadily and neither shows signs of being considered complete; the entries give no indication of another breaking restructure.

◆Recent moves

  1. 2y ago

    New decay_logistic() function; tibble input bug fixed

    A logistic decay function joins the family of distance-decay specifications, and land use data passed as a tibble no longer errors. The note that the package description was rewritten to match its current features is a small acknowledgement of how far the scope has moved since 1.0.0.

    View source ↗
  2. 2y ago

    spatial_availability() can return origin-destination detail

    A detailed_results parameter lets spatial_availability() report per origin-destination pair instead of aggregating by origin, and exposes the demand, impedance and combined balancing factors behind the calculation. It follows the package's habit of making intermediate quantities inspectable rather than hiding them.

    View source ↗
  3. 2y ago

    Concentration index and Theil T join the inequality metrics

    Two more inequality measures extend the family opened in 1.1.0, confirming that distributional analysis is a permanent part of the package rather than a one-off addition. Documentation tweaks and much faster tests ship alongside.

    View source ↗
  4. 3y ago

    Inequality and poverty estimation added to accessibility analysis

    ⚡ SPARK

    This is where the package stops being only about reachability: palma_ratio(), gini_index() and fgt_poverty() bring distributional analysis in, while spatial_availability() and balancing_cost() add competition-aware accessibility measures. The same release makes nearly every parameter accept vectors or lists, which is what allows scenario sweeps to be expressed in a single call.

    View source ↗
  5. 3y ago

    cost_to_closest() fills unreachable ids with Inf, not NA

    Missing ids that cannot reach any opportunity were filled with NA instead of Inf, which also produced a spurious warning. A correctness fix on the metric semantics established by the 1.0.0 rewrite.

    View source ↗
  6. 4y ago

    1.0.0 splits inputs into travel matrix and land use data

    ⚡ SPARK

    The rewrite that defines everything after it: accessibility functions now take a travel_matrix and land_use_data instead of one combined dataset, and most functions and parameters are renamed. It is the point where the package settled the data model that later inequality and availability work was built on.

    View source ↗