Traccess

Transportation access and equity computations.

Traccess offers a set of fast and convenient functions to calculate multiple transport accessibility measures. Given a pre-computed travel cost matrix, and using data sets on land use supply, demand, and demographics, the package computes accessibility levels using multiple accessibility measures, such as: cumulative opportunities, minimum travel cost to closest n number of activities, gravity-based (with different decay functions) and different floating catchment area methods.

The package also contains a number of different methods for computing distributive and sufficientarian equity measures to compare the level of access provided across demographic groups.

Decay functions

traccess.decay provides weighting functions for AccessComputer.cumulative_decay, mirroring IPEA's R accessibility package: binary, exponential, linear, logistic, power and stepped. A missing (NaN) travel cost always gets weight 0.

Equity and inequality measures

EquityComputer computes, once per demographic group:

• Sufficientarian measures: fgt_poverty, in_poverty, poverty_index
• Distributive summaries: weighted_average, weighted_quantile
• Inequality indices (ported from R accessibility): gini_index, theil_t, theil_t_decomposition (between/within a categorical grouping), palma_ratio and concentration_index (both ranked by an income-per-capita or other socioeconomic column)

Pass population_columns to choose which demographic columns are population counts, e.g. when the demographic data also holds an income column.