Accessibility graphs

Elements of a graph

nodes and edges

Graphs encoding spatial weights

Nodes

Geometries (points, lines, or polygons)

Edges

Spatial interactions (contiguity, distance, or regimes)

Graphs encoding spatial networks

Nodes

Junctions

Edges

Links connecting them (streets, paths, transit lines, or rivers)

(pseudo)planar graphs

Undirected

Directed

Multigraphs

Self-loops

Graphs encoding street networks

Nodes

Street junctions

Edges

Street segments (junction-to-junction)

Edge attributes

distance, time, mode of transport, price, slope

routing can take them all into account

Multi-modal networks

General Transit Feed Specification (GTFS)

a community-driven open standard
for rider-facing transit information

import pandarm

import r5py