How systragroup/quetzal works
Quetzal is a transport-planning and traffic-forecasting library. A planner supplies GTFS, road, zoning, and demand inputs; the transport model prepares networks, generates OD demand, performs road and public-transport routing, applies modal choice, and produces level-of-service, analytical, and GIS results. The tree also shows optional Linedraft, ITSIM, and directions-service clients. Several orchestration details were unsampled, so optional links are kept separate or omitted.
Components 24
Inputs and Spatial
- GTFS Import
quetzal/io/gtfs_reader/gtfs_importer.py - Road Input
quetzal/io/road.py - Spatial Preparation
syspy/spatial/spatial.py
Model Orchestration
- Transport Model
quetzal/model/transportmodel.py - OD Demand
quetzal/engine/engine.py - Network Assembly
quetzal/engine/engine.py
Routing and Assignment
- Road Assignment
quetzal/engine/road_pathfinder.py - Transit Routing
quetzal/engine/pathfinder.py - Park Ride Routing
quetzal/engine/park_and_ride_pathfinder.py - Time Expanded Routing
quetzal/engine/time_expanded_utils.py
Analysis and Outputs
- Modal Split
quetzal/engine/engine.py - Nested Choice
quetzal/engine/nested_logit.py - LOS Analysis
quetzal/analysis/analysis.py - Cost Benefit
quetzal/analysis/cost_benefit_analysis.py - GIS Export
quetzal/io/export.py
External Integrations
- Linedraft Client
syspy/clients/linedraft_client/linedraft_client.py - ITSIM Client
syspy/clients/itsim_client/itsim_client.py - Directions Proxy
syspy/clients/api_proxy.py
Other components
- Transport Planner
- GTFS Data
- Network Data
- Linedraft API
- ITSIM API
- Directions API
Connections 20
- Transport Planner → Transport Model: runs model
- GTFS Data → GTFS Import: loads feed
- Network Data → Road Input: loads network
- GTFS Import → Transport Model: provides transit
- Road Input → Network Assembly: provides roads
- Spatial Preparation → Network Assembly: builds geometry
- Transport Model → OD Demand: computes demand
- Transport Model → Network Assembly: prepares network
- Transport Model → Road Assignment: runs assignment
- Transport Model → Transit Routing: runs routing
- Transport Model → Park Ride Routing: runs park ride
- Transport Model → Time Expanded Routing: expands time
- Transport Model → Modal Split: computes split
- Transport Model → Nested Choice: applies choice
- Transport Model → LOS Analysis: analyzes volumes
- Modal Split → GIS Export: exports shares
- LOS Analysis → Cost Benefit: supports appraisal
- Linedraft Client → Linedraft API: requests project data
- ITSIM Client → ITSIM API: requests feeds
- Directions Proxy → Directions API: requests routes