14. Network Analysis¶

Goal: Solve real-world transportation problems — routing, service areas, closest facility, and OD matrices.

What you need¶

• The Network Analyst extension (included with most ArcGIS Pro licenses)
• A network dataset (a road network with travel costs)
• Built locally from a road shapefile/feature class, OR
• Esri-hosted (via ArcGIS Online → Travel Modes) — uses ArcGIS Online credits

The 5 solvers¶

flowchart LR
    R[Route] -.->|"Best path A → B → C → D"| RU[Single trip]
    SA[Service Area] -.->|"All places within 10 min"| SAU[Service polygon]
    CF[Closest Facility] -.->|"Nearest 3 hospitals"| CFU[Distances]
    OD[OD Cost Matrix] -.->|"Each origin to each destination"| ODU[Big distance table]
    LA[Location-Allocation] -.->|"Optimal facility siting"| LAU[Best N sites]

    classDef solver fill:#4338ca,stroke:#312e81,color:#fff
    class R,SA,CF,OD,LA solver

Workflow (any solver)¶

1. Create a network analysis layer (Analysis ribbon → Network Analysis dropdown).
2. Add input features:
   • Route → Stops
   • Service Area → Facilities
   • Closest Facility → Incidents + Facilities
   • OD Cost Matrix → Origins + Destinations
3. Set parameters in the Properties pane (cutoff, mode, breaks).
4. Run (the green play button).
5. Inspect the output (a sub-layer like Routes or Polygons).

Practical examples¶

"10-minute drive-time service area for each fire station"¶

1. New Service Area analysis.
2. Travel mode: Driving Time.
3. Cutoffs: 10 minutes.
4. Add fire stations as facilities.
5. Solve. Output is a polygon per facility.

"Distance from every census block centroid to the nearest grocery store"¶

1. New OD Cost Matrix.
2. Origins: block centroids (~5,000 features).
3. Destinations: grocery stores (~150 features).
4. Cutoff: 30 minutes.
5. Mode: Walking.
6. Solve. Output is a table with origin ID, destination ID, and travel time.

→ Used in Food Desert Analysis.

"What's the optimal route to deliver these 12 packages?"¶

1. New Route.
2. Add 13 stops (depot + 12 deliveries).
3. Tick Reorder Stops to Find Optimal Route.
4. Solve.

Travel modes¶

Credits and limits¶

ArcGIS Online travel modes use credits:

• Route: ~0.5 credits per route
• Service Area: ~0.5 credits per facility
• OD Cost Matrix: ~0.0005 credits per pair (5,000 origins × 150 dests = ~3.75 credits)

Always run with a small subset first to confirm the result is correct before solving the full problem.

Local network datasets¶

For offline / unlimited use, build a network dataset from a road shapefile:

1. Convert to a network dataset (Create Network Dataset tool).
2. Define connectivity, turn restrictions, and cost attributes (e.g., FT/TF travel time).
3. Build the network (Build Network tool).

This is more work but gives you a free, fast, customizable network.

Common pitfalls¶

Practice¶

→ Next: Raster Analysis.