Network from shapefile

This tutorial shows how to create a road network from a shapefile using RA2CE. You can use this workflow when you already have a geospatial dataset (instead of downloading from OpenStreetMap).

Note: Make sure your shapefile contains valid road geometries (e.g. LineString) and that it’s projected in a suitable CRS (e.g. UTM). For more information on projections, see the CRS documentation.

Step 1. Import the Required Packages

from pathlib import Path
import geopandas as gpd
import matplotlib.pyplot as plt

from ra2ce.network.network_config_data.network_config_data import (
    NetworkSection, NetworkConfigData
)
from ra2ce.network.network_config_data.enums.source_enum import SourceEnum
from ra2ce.ra2ce_handler import Ra2ceHandler

Step 2. Define Paths and Network Configuration

Indicate the path to the root directory of your project and to the network shapefile. We recommend to follow the structure shown in the Getting Started Guide.

As a user, define the network configuration using the NetworkConfigData and NetworkSection classes.

root_dir = Path("data", "network_from_shapefile")
network_path = root_dir / "network"

network_section = NetworkSection(
    source=SourceEnum.SHAPEFILE,
    primary_file=network_path.joinpath("base_shapefile.shp"),
    save_gpkg=True,
)

network_config_data = NetworkConfigData(
    root_path=root_dir,
    static_path=root_dir.joinpath("static"),
    network=network_section,
)

Step 3. Initialize and Configure RA2CE

Running the configure method from the Ra2ceHandler will generate the network and store the results in the static/output_graph folder.

handler = Ra2ceHandler.from_config(network=network_config_data, analysis=None)
handler.configure()

Step 4. Load and Inspect the Output

A few geopackages are created in the static/output_graph folder, you can load and inspect them using geopandas.

path_output_graph = root_dir / "static" / "output_graph"
base_graph_edges = path_output_graph / "base_graph_edges.gpkg"
edges_gdf = gpd.read_file(base_graph_edges, driver = "GPKG")

base_graph_nodes = path_output_graph / "base_graph_nodes.gpkg" #specify where to find the nodes file
nodes_gdf = gpd.read_file(base_graph_nodes, driver = "GPKG") #read in the nodes file

Step 5. Plot Nodes and Edges

fig, ax = plt.subplots(figsize=(15, 15))

# Plot edges first
baseplot = edges_gdf.plot(ax=ax, color="grey")

# Overlay nodes
nodes_gdf.plot(ax=baseplot, color="blue", markersize=20)

plt.show()