Route Choice set generation

In this example, we show how to generate route choice sets for estimation of route choice models, using a a city in La Serena Metropolitan Area in Chile.

References

• Route Choice

See also

Several functions, methods, classes and modules are used in this example:

• aequilibrae.paths.RouteChoice()

# Imports
from uuid import uuid4
from tempfile import gettempdir
from os.path import join

import folium
import numpy as np
from aequilibrae.utils.create_example import create_example

# We create the example project inside our temp folder
fldr = join(gettempdir(), uuid4().hex)

project = create_example(fldr, "coquimbo")

Model parameters

Let’s select a set of nodes of interest

od_pairs_of_interest = [(71645, 79385), (77011, 74089)]
nodes_of_interest = (71645, 74089, 77011, 79385)

Let’s build all graphs

project.network.build_graphs()
# We get warnings that several fields in the project are filled with NaNs.
# This is true, but we won't use those fields.

/opt/hostedtoolcache/Python/3.10.17/x64/lib/python3.10/site-packages/aequilibrae/paths/graph.py:247: UserWarning: Found centroids not present in the graph!
  warnings.warn("Found centroids not present in the graph!")
/opt/hostedtoolcache/Python/3.10.17/x64/lib/python3.10/site-packages/aequilibrae/paths/graph.py:247: UserWarning: Found centroids not present in the graph!
  warnings.warn("Found centroids not present in the graph!")

We grab the graph for cars

graph = project.network.graphs["c"]

# we also see what graphs are available
project.network.graphs.keys()

graph.set_graph("distance")

# We set the nodes of interest as centroids to make sure they are not simplified away when we create the network
graph.prepare_graph(np.array(nodes_of_interest))

Route Choice class

Here we’ll construct and use the Route Choice class to generate our route sets

from aequilibrae.paths import RouteChoice

This object construct might take a minute depending on the size of the graph due to the construction of the compressed link to network link mapping that’s required. This is a one time operation per graph and is cached.

rc = RouteChoice(graph)

It is highly recommended to set either max_routes or max_depth to prevent runaway results.

We’ll also set a 5% penalty (penalty=1.05), which is likely a little too large, but it creates routes that are distinct enough to make this simple example more interesting.

rc.set_choice_set_generation("bfsle", max_routes=5, penalty=1.05)
rc.prepare(od_pairs_of_interest)
rc.execute(perform_assignment=True)

choice_set = rc.get_results()

If we were interested in storing the route choice result, we could also write them to disk using the save_path_files method.

# rc.save_path_files(path)

From those path files we could also preform a full assignment or select link analysis by using the execute_from_path_files method.

# rc.execute_from_path_files(path)

Or if we had externally computed route choice sets, we can use AequilibraEs assignment procedures by loading them with the ``execute_from_pandas` method.

# rc.execute_from_pandas(path_files_df)

Plotting choice sets

Now we will plot the paths we just created for the second OD pair

# We get the data we will use for the plot: links, nodes and the route choice set
plot_routes = choice_set[(choice_set["origin id"] == 77011)]["route set"].values

links = project.network.links.data

# For ease of plot, we create a GeoDataFrame for each route in the choice set
route_1 = links[links.link_id.isin(plot_routes[0])]
route_2 = links[links.link_id.isin(plot_routes[1])]
route_3 = links[links.link_id.isin(plot_routes[2])]
route_4 = links[links.link_id.isin(plot_routes[3])]
route_5 = links[links.link_id.isin(plot_routes[4])]

nodes = project.network.nodes.data
nodes = nodes[nodes["node_id"].isin([77011, 74089])]

map = route_1.explore(color="red", style_kwds={"weight": 3}, name="route_1")
map = route_2.explore(m=map, color="blue", style_kwds={"weight": 3}, name="route_2")
map = route_3.explore(m=map, color="green", style_kwds={"weight": 3}, name="route_3")
map = route_4.explore(m=map, color="purple", style_kwds={"weight": 3}, name="route_4")
map = route_5.explore(m=map, color="orange", style_kwds={"weight": 3}, name="route_5")

map = nodes.explore(m=map, color="black", style_kwds={"radius": 5, "fillOpacity": 1.0}, name="network_nodes")

folium.LayerControl().add_to(map)
map

Make this Notebook Trusted to load map: File -> Trust Notebook

project.close()

This project at /tmp/9b9d5fc5b9f74c4db0f11cec1efc6d1f is already closed