ferrobus.calculate_percent_access_isochrone

ferrobus.calculate_percent_access_isochrone#

ferrobus.calculate_percent_access_isochrone(transit_model, start_point, departure_range, sample_interval, max_transfers, cutoff, index)#

Calculate percentage-based accessibility across multiple departure times

Computes how frequently each cell in the area is accessible across a range of departure times, producing a heat map of transit reliability.

Parameters:

  • transit_model (TransitModel) – The transit model to use for routing.

  • start_point (TransitPoint) – Starting location for the isochrone.

  • departure_range (tuple(int, int)) – Range of departure times to sample (start_time, end_time) in seconds.

  • sample_interval (int) – Time interval between samples in seconds.

  • max_transfers (int) – Maximum number of transfers allowed in route planning.

  • cutoff (int) – Maximum travel time in seconds to include in the isochrone.

  • index (IsochroneIndex) – Pre-computed isochrone spatial index for the area.

Returns:

GeoJSON FeatureCollection string containing polygons for each grid cell with properties indicating the percentage of sampled times the cell was accessible.

Return type:

str

Raises:

RuntimeError – If isochrone calculation fails.

Notes

This function is useful for analyzing transit reliability and service frequency across different times of day.