gmns-ready 0.1.0
Tools for preparing and validating GMNS transportation network data
License: MIT
Requires Python: >=3.7
Keywords: transportation, gmns, network-modeling, open-source, urban-planning, traffic-assignment

# GMNS Ready

**Professional toolkit for preparing and validating GMNS transportation networks with complete zone connectivity.**

[![Python Version](https://img.shields.io/badge/python-3.7%2B-blue)](https://www.python.org/downloads/)
[![Tutorial 1](https://img.shields.io/badge/tutorial-Traffic%20Assignment-yellow)](https://colab.research.google.com/drive/1sSdlliVKIBt7-Uke2DnbJ3oZgDF8P289?usp=drive_link)
[![Tutorial 2](https://img.shields.io/badge/tutorial-POI%20Accessibility-orange)](https://colab.research.google.com/drive/115qvdnJNLR5YWojy7DqgyUDbWOEH0Zl7?usp=sharing)

## Table of Contents

- [GMNS Ready](#gmns-ready)
  - [Overview](#overview)
  - [Installation](#installation)
  - [Quick Start](#quick-start)
  - [Supported Input Sources](#supported-input-sources)
  - [Application Scenarios](#application-scenarios)
    - [Scenario 1: Traffic Assignment](#scenario-1-traffic-assignment)
    - [Scenario 2: POI Accessibility Analysis](#scenario-2-poi-accessibility-analysis)
  - [The 7-Step Pipeline](#the-7-step-pipeline)
    - [STEP 1: Import Network](#step-1-import-network)
    - [STEP 2: Standardize to GMNS Schema](#step-2-standardize-to-gmns-schema)
    - [STEP 3: Construct Zones (Z)](#step-3-construct-zones-z)
    - [STEP 4: Identify Internal Activity Nodes (IA)](#step-4-identify-internal-activity-nodes-ia)
    - [STEP 5: Convert EA → Z_E](#step-5-convert-ea--z_e)
    - [STEP 6: Generate Connectors (C)](#step-6-generate-connectors-c)
    - [STEP 7: Build Final Unified Output](#step-7-build-final-unified-output)
  - [Mathematical Framework](#mathematical-framework)
  - [Tutorial](#tutorial)
  - [Core Functions](#core-functions)
    - [1. Input Validation](#1-input-validation)
    - [2. Zone Data Processing](#2-zone-data-processing)
    - [3. Network Building](#3-network-building)
    - [4. Network Validation](#4-network-validation)
    - [5. Connectivity Enhancement](#5-connectivity-enhancement)
  - [Network Preparation](#network-preparation)
  - [Complete Workflow Example](#complete-workflow-example)
  - [Project Structure](#project-structure)
  - [Function Reference](#function-reference)
  - [Integration with Other Tools](#integration-with-other-tools)
    - [osm2gmns](#working-with-osm2gmns)
    - [shp2gmns](#working-with-shp2gmns-transcadshapefile-workflows)
    - [OSMNX + Network Wrangler](#working-with-osmnx--network-wrangler)
    - [TNTP Benchmark Networks](#working-with-tntp-benchmark-networks)
  - [Requirements](#requirements)
  - [GMNS Compliance](#gmns-compliance)
  - [Citation](#citation)
  - [Contributing](#contributing)
  - [Authors](#authors)
  - [Acknowledgments](#acknowledgments)

## Overview

`gmns-ready` is a comprehensive Python package that prepares, validates, and enhances GMNS (General Modeling Network Specification) transportation networks. It automates the critical but often manual process of connecting traffic analysis zones to road networks, ensuring your data is ready for traffic assignment and travel demand modeling.

**Key Capabilities:**
- ✅ Validate spatial alignment before processing
- ✅ Extract and process zone data from shapefiles with automatic detection
- ✅ Generate zone-to-network connectors following Forward Star structure
- ✅ Validate network integrity and accessibility using DTALite
- ✅ Enhance connectivity for zones with limited network access
- ✅ Prepare networks for traffic assignment with VDF parameter validation
- ✅ Cross-platform support (Windows, Linux, macOS)

## Installation

```bash
pip install gmns-ready
```

This will automatically install all required dependencies including [DTALite](https://pypi.org/project/DTALite/) for accessibility validation.

**New to gmns-ready?** Check out our [interactive tutorial on Google Colab](https://colab.research.google.com/drive/1sSdlliVKIBt7-Uke2DnbJ3oZgDF8P289?usp=drive_link) - no installation required!

Or install from source:
```bash
git clone https://github.com/hhhhhenanZ/gmns_ready.git
cd gmns_ready
pip install -e .
```

## Quick Start

```python
import gmns_ready as gr

# Step 1: Validate inputs are spatially aligned
gr.validate_basemap()

# Step 2: Extract zones from shapefile (auto-detects .shp in data/ folder)
gr.extract_zones()

# Step 3: Build zone-connected network
gr.build_network()

# Step 4: Validate everything
gr.validate_network()
gr.validate_accessibility()  # Uses DTALite for traffic assignment
gr.validate_assignment()
```
---
## 📊 Supported Input Sources

gmns-ready is designed to work with data from multiple agencies and modeling tools:

| **Source** | **Typical Users** | **Status** |
|------------|-------------------|-----------|
| **OSM → osm2gmns** | Researchers, universities, open-data projects | Supported |
| **TransCAD Shapefiles (via shp2gmns)** | State DOTs, MPOs  | Supported |
| **OSMNX + Network Wrangler** | SFCTA, Caltrans, Bay Area agencies | Supported |
| **TNTP Networks** | Academic benchmarks | Supported |
| **Custom CSV** | Legacy systems, proprietary formats | Supported |

**Key Insight:** All sources are converted to the same internal standardized structure, enabling seamless interoperability.

---
## 📋 Application Scenarios

### **Scenario 1: Traffic Assignment**

**Purpose:** Connect zone centroids to physical transportation network for dynamic/static traffic assignment.

**Input Files:**
- `node.csv`, `link.csv` — Generated by osm2gmns from OpenStreetMap data (Physical network)
- `zones.shp` — TAZ (Traffic Analysis Zones), Census Tracts, or custom zone boundaries

**Network Structure:**
```
N = P ∪ Z  where P ∩ Z = ∅
```

**Components:**
- **Zone Centroids (Z):** Trip generation/attraction points from planning layer
- **Physical Network Nodes (P):** Infrastructure nodes from osm2gmns
- **Internal Activity Nodes (IA ⊂ P):** Auto-identified access points within physical network
  - Located at arterial/local intersections
  - Network boundaries
  - Functional class transition points
- **Connectors (L_C):** Virtual links connecting Z → IA

**Use Cases:**
- Regional traffic forecasting
- Congestion analysis
- Travel time estimation
- Peak-hour flow simulation

**Mathematical Framework:**
```
Z = {z₁, z₂, ..., zₙ}  (zone centroids)
P = {p₁, p₂, ..., pₘ}  (physical network nodes)
IA ⊂ P                  (internal activity nodes - subset of physical nodes)
Connectors: C(Z, P)
```

---

### **Scenario 2: POI Accessibility Analysis**

**Purpose:** Analyze accessibility to specific points of interest (parks, schools, hospitals, transit stops, markets).

**Input Files:**
- `node.csv`, `link.csv` — Physical network from osm2gmns (same as Scenario 1)
- `poi.shp` or `poi.csv` — External access points (bus stops, park gates, school entrances)
  - Renamed as `zone.csv` in your local folder alongside node.csv and link.csv

**Network Structure:**
```
N = P ∪ Z_E  where all sets are disjoint
```

**Key Transformation:**
```
φ: EA → Z_E  (External access points promoted to zones)
```

**Components:**
- **External Access Points (EA):** User-provided POI shapefile/CSV
- **External Zones (Z_E):** Each EA converted to micro-zone via φ transformation
- **Connectors:** Two types
  - Z → IA (traditional trip loading)
  - Z_E → P (nearest physical node connection)

**Critical Constraint:**
```
Z_E ∩ P = ∅  (External zones must NOT overlap with OSM network nodes)
```
**Use Cases:**
- Transit equity studies (distance to bus stops)
- Facility accessibility
- 15-minute city planning

---

## 🔄 The 7-Step Pipeline

This workflow applies to **all input sources** (OSM, TransCAD, Wrangler, TNTP, Custom):

### **STEP 1: Import Network**

Supports multiple import pathways:
- **OSM2GMNS:** node.csv, link.csv from OpenStreetMap
- **shp2gmns:** TransCAD/ArcGIS shapefiles
- **osmnx:** Graph export to CSV (nodes, edges)
- **Network Wrangler:** `OUT_DIR/hwy` or `OUT_DIR/trn` outputs
- **TNTP:** `.tntp` format (nodes.tntp, links.tntp)
- **Custom CSV:** Generic CSV reader with configuration

All imports convert to the same internal object model.

---

### **STEP 2: Standardize to GMNS Schema**

Automated transformations:
- Rename fields to GMNS standard
- Assign node types (boundary, signalized intersection, etc.)
- Clean duplicate IDs
- Establish consistent CRS (coordinate reference system)
- Validate link direction and topology

---

### **STEP 3: Construct Zones (Z)**

**For Scenario 1 (DTA):**
- Load TAZ shapefile
- Generate zone centroids
- Assign zone attributes

**For Scenario 2 (POI):**
- Load external access points (EA)
- Transform: φ(EA) → Z_E
- Verify Z_E ∩ P = ∅
- Treat POIs as micro-zones

---

### **STEP 4: Identify Internal Activity Nodes (IA)**

**Auto-identification criteria:**
- Functional class boundaries (e.g., arterial ↔ local transition)
- External boundaries (city limits, study area edges)
- Entrance logic (freeway ramps, major intersections)
- MPO-provided "access node" lists (if available)

**Key principle:** IA ⊂ P (not a separate file)

---

### **STEP 5: Convert EA → Z_E** *(Scenario 2 only)*

External access nodes (park gates, bus stops, schools) are promoted to zones:
- **EA → Z_E** transformation via function φ
- Each Z_E connects to nearest physical node (P)
- Avoids double-counting
- Maintains clean model logic

---

### **STEP 6: Generate Connectors (C)**

**Two connector types:**

1. **Z → IA connectors** (for trip loading)
2. **Z_E → P connectors** (for external POIs)
   - Connects to nearest physical network node
   - Ensures accessibility calculations include POIs

**Validation:**
- Every zone must have at least one connector
- No connector-less zones allowed

---

### **STEP 7: Build Final Unified Output**

**Output Files:**
- `node.csv` — Contains P, IA, Z, Z_E (all node types)
- `link.csv` — Contains L_P (physical links) + L_C (connectors)
- `zone.csv` — Zone definitions and attributes
- `connector_links.csv` — Detailed connector information

**Ready for:**
- Accessibility analysis
- Traffic assignment and simulation
- Network Wrangler scenario management

---

## 📐 Mathematical Framework
### **Notation Reference**

| Symbol | Type | Definition |
|--------|------|------------|
| **P** | Set | Physical network nodes (from osm2gmns or other sources) |
| **Z** | Set | Zone centroids (trip generation/attraction areas) |
| **IA** | Subset | Internal activity nodes: IA ⊂ P (auto-identified access points) |
| **EA** | Set | External access points (user-provided POIs) |
| **Z_E** | Set | External zones: φ(EA) = Z_E (EA promoted to zones) |
| **L_P** | Set | Physical links (road segments) |
| **L_C** | Set | Connectors (virtual links between zones and network) |
| **φ** | Function | Transformation: EA → Z_E (converts external points to zones) |

### **Critical Constraints**

```
Disjoint Sets:     P ∩ Z = ∅,  P ∩ Z_E = ∅,  Z ∩ Z_E = ∅
Completeness:      ∀z ∈ Z ∪ Z_E: ∃c ∈ L_C
Activity Nodes:    IA ⊂ P (not a separate node type)
Non-Overlapping:   External POI locations must not coincide with existing OSM nodes
```

---
## Tutorial

**Interactive Tutorial:** Try our hands-on [Google Colab tutorial](https://colab.research.google.com/drive/1sSdlliVKIBt7-Uke2DnbJ3oZgDF8P289?usp=drive_link) to learn how to use gmns-ready with real examples.

---

## Core Functions

### 1. Input Validation

**`validate_basemap()`** - Verify spatial alignment of input files

Checks that node.csv, link.csv, and zone shapefiles are in the same geographic area before processing. This prevents common errors from misaligned data sources and saves troubleshooting time.

```python
import gmns_ready as gr

gr.validate_basemap()  # Checks files in current directory
```

**When to use:** FIRST step before any processing

**Inputs:**
- `node.csv` and `link.csv` in current directory
- Any `.shp` file in `data/` folder

**Output:** `data/base_map_validation_report.json`

**What it checks:**
- Coordinate system consistency
- Geographic overlap of all datasets
- Bounding box alignment

---

### 2. Zone Data Processing

**`extract_zones()`** - Extract zone centroids and boundaries from shapefile

Automatically detects and processes zone shapefiles (census tracts, TAZs, etc.) from the `data/` folder. Calculates centroids, preserves boundaries, and generates GMNS-compliant zone.csv with automatic coordinate projection to EPSG:4326.

```python
import gmns_ready as gr

gr.extract_zones()  # Auto-detects .shp file in data/ folder
```

**Inputs:**
- Any `.shp` file in `data/` folder (auto-detected)
- Supports multiple shapefile types: census tracts, TAZ, custom zones

**Outputs:**
- `zone.csv` with zone_id, x_coord, y_coord, boundary_geometry (WKT)

**Features:**
- Auto-detects zone ID column (TRACTCE, GEOID, TAZ, etc.)
- Reprojects to EPSG:4326 automatically
- Preserves both centroid points and boundary polygons

---

**`extract_zones_pop()`** - Add population data to zones (US only)

Fetches and adds demographic data from ACS 2022 API for US zones. Outputs the same zone.csv with an additional population column.

```python
import gmns_ready as gr

gr.extract_zones_pop()  # Uses .shp from data/, adds population column
```

**Inputs:**
- Any `.shp` file in `data/` folder (auto-detected)

**Outputs:**
- `zone.csv` with all zone data + population column

**Note:** Only works for US locations. Population data does not affect network connectivity.

---

### 3. Network Building

**`build_network()`** - Generate zone-connected network with connectors

The core function that creates a complete zone-connected network following [Forward Star Network Structure](https://github.com/asu-trans-ai-lab/TAPLite/wiki/Forward-Star-Network-Structure:-Centroid-Nodes-and-Connectors). Connects each zone to the nearest road network nodes and creates activity nodes for demand generation.

```python
import gmns_ready as gr
# Uses zone.csv, node.csv, link.csv from current directory
# Default: 1000m search radius
gr.build_network()

# Custom search radius for different urban contexts
gr.build_network(zone_search_radius=500)   # Dense urban areas
gr.build_network(zone_search_radius=1500)  # Suburban areas
gr.build_network(zone_search_radius=None)  # Unlimited (rural areas)
```

**Prerequisites:**
- `zone.csv` from `extract_zones()`
- `node.csv` and `link.csv` from [osm2gmns](https://github.com/asu-trans-ai-lab/osm2gmns)

**Parameters:**
- `zone_search_radius` (float or None, default=1000): Search radius in meters for connecting zones without activities to road network
  - **500m**: Dense urban cores with high road density
  - **1000m**: Mixed urban/suburban areas (default, recommended)
  - **1500m**: Suburban or low-density areas
  - **None**: Unlimited search (always find nearest link, best for rural areas)

**Outputs:** `connected_network/` folder containing:
- `node.csv` - Network nodes + activity nodes + zone centroids
- `link.csv` - Road links + connector links
- `activity_node.csv` - Activity nodes (trip generation points)
- `connector_links.csv` - Connector links only

**What it does:**
- Connects each zone centroid to nearest network nodes
- Creates activity nodes from OSM POIs (residential, commercial, educational, transit locations)
- Ensures bidirectional connectivity between zones and network
- Maintains GMNS format compliance

**Key concept:** Activity nodes are OSM-derived points of interest that represent where trips begin or end in GMNS-based demand modeling.

---

### 4. Network Validation

**`validate_network()`** - Check network structure and topology

Validates network topology, node-link consistency, connectivity, and GMNS format compliance for the zone-connected network.

```python
import gmns_ready as gr

gr.validate_network()  # Checks connected_network/ folder
```

**Output:** `connected_network/network_validation_report.json`

**What it checks:**
- Node-link topology consistency
- Network connectivity (all zones reachable)
- GMNS format compliance
- Data integrity

---

**`validate_accessibility()`** - Analyze zone-to-zone connectivity using DTALite

Runs traffic assignment using [DTALite](https://pypi.org/project/DTALite/) to compute zone-to-zone accessibility matrix and identify connectivity issues. This validation uses the DTALite Python package for cross-platform support (Windows, Linux, macOS).

```python
import gmns_ready as gr

gr.validate_accessibility()  # Checks connected_network/ folder
```

**Requirements:**
- DTALite package (auto-installed with gmns-ready)
- `settings.csv` in GMNS_Tools folder or network directory
- `connected_network/node.csv` and `link.csv`

**Outputs:**
- `connected_network/zone_accessibility.csv` - Zone-to-zone connectivity metrics
- `connected_network/link_performance.csv` - Traffic assignment results
- `connected_network/accessibility_validation_report.json` - Validation summary

**What it computes:**
- Zone-to-zone reachability matrix
- Origin/destination connectivity for each zone
- Identifies zones with poor accessibility (<10% of total zones)

**Check results:** Review the report to identify zones that may need additional connectors.

**DTALite:** [DTALite](https://pypi.org/project/DTALite/) is a fast, open-source traffic assignment engine that performs dynamic traffic assignment to compute realistic travel patterns and accessibility metrics.

---

**`validate_assignment()`** - Verify traffic assignment readiness

Validates VDF (Volume-Delay Function) parameters and link attributes required for traffic assignment by link type.

```python
import gmns_ready as gr

gr.validate_assignment()  # Checks connected_network/ folder
```

**Output:** `connected_network/assignment_validation_summary.json`

**What it checks:**
- VDF parameters: `vdf_alpha`, `vdf_beta`, `vdf_plf`, `vdf_fftt`
- Link capacity by link_type
- Parameter value ranges and consistency
- Excludes connectors (link_type=0) from validation

---

### 5. Connectivity Enhancement

**`enhance_connectors()`** - Add connectors for poorly connected zones

Adds 10 additional connectors per zone to improve accessibility for zones with poor network connectivity (<10% of total zones). Distributes connectors across road hierarchy: 3 to highways, 3 to arterials, 2 to collectors, 2 to local roads.

```python
import gmns_ready as gr
# Default: 1000m search radius, 10% threshold, 6 connectors per zone
gr.enhance_connectors()

# Urban area: smaller search radius
gr.enhance_connectors(search_radius=500)
# Suburban area: larger search radius
gr.enhance_connectors(search_radius=1500)
# More aggressive enhancement
gr.enhance_connectors(
    search_radius=1500,
    accessibility_threshold=0.15,  # Target zones below 15% connectivity
)
```

**When to use:**
- After running `validate_accessibility()`
- When zones show low connectivity scores (<10% of total zones)
- To improve network coverage for isolated zones

**Parameters:**
- `search_radius` (int, default=1000): Maximum search distance in meters for finding candidate network links
  - **500m**: Dense urban areas (more precise, fewer long connections)
  - **1000m**: Mixed areas (default, balanced approach)
  - **1500m**: Suburban/rural areas (wider search, more connection options)
  
- `accessibility_threshold` (float, default=0.10): Connectivity target as percentage of total zones
  - Zones connecting to fewer than this percentage are enhanced
  - **0.10**: Conservative (10% threshold - enhance only most isolated zones)

**Outputs:**
- `connected_network/link_updated.csv` - Enhanced link file with additional connectors
- `connected_network/connector_editor_report.txt` - Detailed report of added connectors

**Workflow:**
1. Run `enhance_connectors()`
2. Review `link_updated.csv` and report
3. Replace `connected_network/link.csv` with `link_updated.csv`
4. Re-run `validate_accessibility()` to verify improvements
5. Repeat if needed until accessibility requirements are met

---

## Network Preparation

### `clean_network()` - Remove disconnected components from OSM networks

OSM networks extracted via osm2gmns may contain disconnected islands or isolated segments due to data quality issues. This function identifies the main connected component and removes isolated parts, ensuring your network is fully traversable.

```python
import gmns_ready as gr

gr.clean_network()  # Cleans node.csv and link.csv from osm2gmns
```

**When to use:**
- **BEFORE** building zone-connected network
- After extracting network from osm2gmns
- When you suspect OSM data quality issues
- To ensure complete network traversability

**Inputs:**
- `node.csv` and `link.csv` (from osm2gmns in current directory)

**Outputs:** `osm_network_connectivity_check/` folder containing:
- Cleaned `node.csv` and `link.csv` (main connected component only)
- `network_connectivity_analysis.png` - Before/after visualization
- `isolated_components_detail.png` - Detailed view of removed components

**After running:**
Replace your original `node.csv` and `link.csv` with the cleaned versions from `osm_network_connectivity_check/` folder, then proceed to `build_network()`.

---

## Complete Workflow Example

```python
import gmns_ready as gr
import osm2gmns as og

# ============================================================================
# STEP 0: Generate base network from OSM (using osm2gmns)
# ============================================================================
# net = og.getNetFromFile('map.osm')
# og.outputNetToCSV(net)  # Creates node.csv and link.csv

# ============================================================================
# STEP 0.5: Clean OSM network (recommended)
# ============================================================================
gr.clean_network()
# Copy cleaned files from osm_network_connectivity_check/ to project root

# ============================================================================
# STEP 1: Validate spatial alignment
# ============================================================================
gr.validate_basemap()
# Check: data/base_map_validation_report.json

# ============================================================================
# STEP 2: Extract zones
# ============================================================================
gr.extract_zones()
# Output: zone.csv

# Optional: Add population data (US only)
# gr.extract_zones_pop()
# Output: zone.csv with population column

# ============================================================================
# STEP 3: Build zone-connected network
# ============================================================================
gr.build_network()
# Output: connected_network/ folder with all network files

# ============================================================================
# STEP 4: Validate network
# ============================================================================
gr.validate_network()
# Check: connected_network/network_validation_report.json

gr.validate_accessibility()  # Uses DTALite for traffic assignment
# Check: connected_network/accessibility_validation_report.json

gr.validate_assignment()
# Check: connected_network/assignment_validation_summary.json

# ============================================================================
# STEP 5: Enhance connectivity if needed
# ============================================================================
# If accessibility report shows poorly connected zones:
gr.enhance_connectors()
# Output: connected_network/link_updated.csv

# Replace link.csv with link_updated.csv
# import shutil
# shutil.copy('connected_network/link_updated.csv', 'connected_network/link.csv')

# Re-validate
gr.validate_accessibility()

# Repeat enhancement if needed until all zones meet requirements
```

---

## Project Structure

```
your_project/
├── data/
│   ├── zones.shp                    # Input: Zone shapefile (any name)
│   └── base_map_validation_report.json
├── GMNS_Tools/                      
│   └── settings.csv                 # DTALite configuration
├── node.csv                         # From osm2gmns
├── link.csv                         # From osm2gmns
├── zone.csv                         # Generated by extract_zones()
├── osm_network_connectivity_check/  # Optional: cleaned network
│   ├── node.csv
│   ├── link.csv
│   ├── network_connectivity_analysis.png
│   └── isolated_components_detail.png
└── connected_network/               # Final output
    ├── node.csv
    ├── link.csv
    ├── settings.csv                 # Copied from GMNS_Tools
    ├── activity_node.csv
    ├── connector_links.csv
    ├── zone_accessibility.csv       # From DTALite
    ├── link_performance.csv         # From DTALite
    ├── network_validation_report.json
    ├── accessibility_validation_report.json
    ├── assignment_validation_summary.json
    ├── link_updated.csv             # If enhanced
    └── connector_editor_report.txt  # If enhanced
```

---

## Function Reference

### Import Style

```python
# Recommended: Import once, use all functions
import gmns_ready as gr

# Then call any function:
gr.validate_basemap()
gr.extract_zones()
gr.build_network()
gr.validate_network()
gr.validate_accessibility()
gr.validate_assignment()
gr.enhance_connectors()
gr.extract_zones_pop()
gr.clean_network()
```

### Function Summary

| Function | Purpose | When to Use |
|----------|---------|-------------|
| `validate_basemap()` | Check spatial alignment | **FIRST** - before any processing |
| `extract_zones()` | Extract zones from shapefile | After basemap validation |
| `extract_zones_pop()` | Add population to zones | Optional, US only |
| `build_network()` | Create zone-connected network | After zone extraction |
| `validate_network()` | Check network structure | After network building |
| `validate_accessibility()` | Analyze zone connectivity with DTALite | After network building |
| `validate_assignment()` | Check assignment readiness | After network building |
| `enhance_connectors()` | Add more connectors | When accessibility is poor |
| `clean_network()` | Remove isolated components | Before network building (optional) |

---
## 🔗 Integration with Other Tools

### **Working with osm2gmns**

osm2gmns is the primary tool for converting OpenStreetMap data to GMNS format:

```
Step 1: Use osm2gmns to download and convert OSM data
  → Produces: node.csv, link.csv

Step 2: Load into gmns-ready
  → Add zones (TAZ shapefile or POI data)
  → Identify activity nodes (automatic)
  → Generate connectors

Step 3: Export unified network
  → Ready for DTALite or other assignment tools
```

**Compatibility:** gmns-ready is designed as a downstream tool for osm2gmns outputs.

---

### **Working with shp2gmns (TransCAD/Shapefile Workflows)**

Many MPOs and state DOTs use TransCAD or maintain networks as shapefiles:

```
Step 1: Use shp2gmns to convert shapefiles to GMNS
  Input:  network_links.shp, network_nodes.shp
  Output: node.csv, link.csv, segment.csv (if needed)

Step 2: Plug directly into gmns-ready pipeline
  → Standard processing applies
  → Generate zones and connectors
  → Export for assignment
```

**Key benefit:** Legacy TransCAD networks can be modernized to GMNS standard.

---

### **Working with OSMNX + Network Wrangler**

Network Wrangler is used for scenario management by agencies like SFCTA and Caltrans:

```
Step 1: Use osmnx to create graph
  → Export to CSV (nodes, edges)

Step 2: Run Wrangler build script
  python build_network.py network_specification.py
  → Produces GMNS-like outputs in OUT_DIR/hwy or OUT_DIR/trn

Step 3: Ingest Wrangler outputs into gmns-ready
  → Standard format conversion
  → No conflicts — Wrangler is just another importer

Step 4: Apply gmns-ready pipeline
  → Zone integration
  → Connector generation
  → Final export
```

**Key benefit:** Scenario management (via Wrangler) + network preparation (via gmns-ready) work seamlessly together.

---

### **Working with TNTP Benchmark Networks**

TNTP provides standardized test networks widely used in research:

```
Step 1: Download TNTP network
  Files: nodes.tntp, links.tntp

Step 2: Convert to GMNS format using gmns-ready
  → Parse TNTP format
  → Convert to node.csv, link.csv

Step 3: Optionally create synthetic zones
  → Grid-based zone generation for testing

Step 4: Standard pipeline
  → Generate connectors
  → Export unified format
```

**Key benefit:** Academic benchmarks become compatible with modern GMNS tools.
---

## Requirements

```
python >= 3.7
pandas >= 1.3.0
geopandas >= 0.10.0
shapely >= 1.8.0
matplotlib >= 3.3.0
networkx >= 2.6.0
DTALite >= 0.8.1
```

All dependencies are automatically installed with `pip install gmns-ready`.

---

## GMNS Compliance

This package follows the [General Modeling Network Specification (GMNS)](https://github.com/zephyr-data-specs/GMNS) standard, ensuring compatibility with:
- Traffic assignment tools (e.g., [DTALite](https://pypi.org/project/DTALite/))
- Travel demand models
- Network visualization tools
- Other GMNS-compliant software

---

## Citation

If you use this package in your research, please cite:

```bibtex
@software{gmns_ready,
  author = {Zhu, Henan and Zhou, Xuesong and Zheng, Han},
  title  = {GMNS Ready: Professional Toolkit for GMNS Transportation Networks},
  year   = {2025},
  url    = {https://github.com/hhhhhenanZ/gmns_ready}
}
```

---

## Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

## License

MIT License - see [LICENSE](LICENSE) file for details.

## Authors

**Henan Zhu**, **Xuesong Zhou**, **Han Zheng**  
Arizona State University

**Contact:**
- Issues: [GitHub Issues](https://github.com/hhhhhenanZ/gmns_ready/issues)
- Email: henanzhu@asu.edu, xzhou74@asu.edu

## Acknowledgments

- Zephyr Foundation for GMNS standards
- [ASU Transportation + AI Lab](https://github.com/asu-trans-ai-lab) for developing [osm2gmns](https://github.com/asu-trans-ai-lab/osm2gmns) and [DTALite](https://pypi.org/project/DTALite/)