Network analysis is a key part of geographic information systems (GIS) and transportation planning. It uses graph theory to model and analyze the movement of people, goods, and services over a network (like roads, pipelines, or public transit systems). Here are some of the most common types of network analysis:

1. Route Finding (Shortest Path)

• Goal: Find the most efficient path between two or more locations.
• Applications: Navigation systems (Google Maps, Waze), delivery optimization, emergency response.
• Algorithms Used:
  • Dijkstra’s Algorithm
  • A* (A-star) Search
  • Bellman-Ford (for graphs with negative weights)

2. Service Areas (Isochrones)

• Goal: Identify the area that can be reached within a certain time or distance from a point.
• Applications:
  • Emergency service coverage (e.g., fire stations, hospitals)
  • Store catchment areas
  • Accessibility studies
• Methods:
  • Time-based or distance-based thresholds
  • Often visualized as polygons on a map

3. Closest Facility

• Goal: Identify the nearest facility (e.g., hospital, fire station) to a given incident or location.
• Applications: Emergency dispatch, public service access.
• Factors: May include travel time, road conditions, and speed limits.

4. Vehicle Routing Problem (VRP)

• Goal: Determine the optimal set of routes for multiple vehicles to service a set of locations.
• Applications: Logistics, delivery services, waste collection.
• Variations:
  • Capacitated VRP
  • Time Window VRP
  • Pickup and Delivery VRP

5. Origin-Destination (OD) Cost Matrix

• Goal: Calculate cost (distance/time) between multiple origins and multiple destinations.
• Applications: Commuting analysis, trip planning, accessibility modeling.

6. Network Tracing

• Goal: Identify upstream/downstream connections from a given point.
• Applications: Utility networks (e.g., water, gas, electricity), telecom systems.

Tools & Software

• GIS Platforms: ArcGIS Network Analyst, QGIS (with pgRouting or plugins), GRASS GIS
• Libraries:
  • Python: networkx, osmnx, graph-tool, scikit-mobility
  • JavaScript: leaflet-routing-machine, turf.js