High-level functions

get_drive_graph	Build a drivable road network (nx.MultiDiGraph) from OpenStreetMap within a given territory.
get_walk_graph	Build a pedestrian network (nx.MultiDiGraph) from OpenStreetMap within a given territory.
get_all_public_transport_graph	Build a combined directed graph for multiple public-transport modes within a territory.
get_single_public_transport_graph	Build a directed graph for a single public-transport mode within a given territory.
get_intermodal_graph	Build an intermodal (PT+walking) graph for a territory by downloading, parsing, and joining both networks.
join_pt_walk_graph	Join a public-transport graph with a pedestrian graph into a single intermodal network.