ALERT-C Locations Tester
Validation tool for ALERT-C location references in RDS-TMC and DATEX II traffic information
Quick Info
| License | MIT |
| Repository | GitHub Repository |
| Developer | TamTam Research s.r.o. |
| Technology | Python, SQLite, CLI |
Overview
ALERT-C Locations Tester is a validation tool for ALERT-C location references, which were primarily used in RDS-TMC services but have become popular also in other services such as provisioning road traffic information using DATEX II data formats.
The tool generates a location index file from standard TMC format files (ISO/DIS 14819), providing complete enumeration of all possible location references for a given version of location tables. Users can then validate their traffic information content against this index to detect invalid location references that should not be used.
Key Features
- Location index generation: Creates comprehensive indices from TMC format files (.DAT)
- Format-agnostic validation: Works with any traffic information format once location references are extracted
- Multiple output formats: Generates SQLite databases and CSV files for flexible integration
- Comprehensive validation: Checks primary location codes, directionality (+/-), and extent values (0-31)
- Large-scale processing: Handles extensive location tables (45,929+ allocated locations)
- Command-line interface: Easy automation and integration into CI/CD pipelines
- Extensible: Reference implementation for DDR.xml format, adaptable to DATEX II and others
Use Cases
- Data quality assurance: Systematically validate location references before broadcasting or publishing
- Compliance verification: Ensure conformance with ISO/DIS 14819 standard
- Pre-publication testing: Validate traffic information before publishing on National Access Points
- Continuous monitoring: Regular validation to maintain data quality standards
- Format migration: Verify location references when converting between formats
- Development testing: Validate location references during application development
How It Works
Two-Stage Approach
Stage 1: Generate Location Index
# Process TMC location tables to create validation index
inv generate-index --location-table=path/to/table.DATOutput: SQLite database and CSV file containing all valid location references
Stage 2: Validate References
# Extract location references from your traffic data
# Compare against the generated index
inv validate --content=path/to/traffic-data.xmlInvalid References Detected
The tool identifies various types of invalid location references:
- Extent values above 31: Maximum allowed extent is 31
- Non-existent primary location codes: e.g., location code 0
- Invalid combinations: Primary location, direction, and extent that don't exist together
- Undefined locations: References to locations not defined in the location table version
- Out-of-range values: Any values outside the valid ranges defined by the standard
Standards Supported
Target Audience
- Organizations operating RDS-TMC services across Europe
- National Access Points managing DATEX II traffic information with ALERT-C referencing
- Traffic information service providers
- Road infrastructure authorities
- NAP operators ensuring data quality
- Developers implementing traffic information systems
Technical Details
Technology Stack
- Language: Python
- Database: SQLite for efficient index storage
- CLI Framework: Invoke package for command-line interface
- Input Format: TMC location tables (.DAT files) conforming to ISO/DIS 14819
- Output Formats: SQLite database, CSV files
Location Table Format
The tool processes TMC location tables in standard .DAT format according to ISO/DIS 14819. These tables contain:
- Primary location codes
- Direction information
- Extent specifications
- Location metadata
Validation Components
The tool validates three key components:
- Primary location codes: Must exist in the location table
- Directionality: Positive (+) or negative (-) direction
- Extent values: Must be between 0 and 31
Example Implementation
The repository includes a reference implementation for DDR.xml (legacy Czech format), which can serve as a template for:
- Extracting location references from DATEX II XML
- Processing other traffic information formats
- Integrating validation into existing workflows
Location Table Availability
Location Tables Not Included
ALERT-C location tables are not included in the repository due to licensing restrictions. They are typically available from national traffic information centers.
Example - Czech Location Tables: Available for free after signing a license agreement at: Czech NDIC TMC Location Table
Contact your national traffic information center for location tables in other countries.
Operational Use
- Production deployment: Currently in operational use by Czech Road and Motorway Directorate (ŘSD)
- Initial funding: Development funded by Ředitelství silnic a dálnic s.p. (Czech Road and Motorway Directorate)
- Proven reliability: Validates thousands of location references in production environment
Why This Tool Matters
ALERT-C Locations Tester addresses a critical data quality challenge in European road traffic information systems:
Data Quality Assurance
Systematic validation prevents broadcasting incorrect location information that could mislead drivers and compromise road safety.
European Relevance
ALERT-C is widely used for road traffic location referencing across Europe, both in traditional RDS-TMC and modern DATEX II services.
Format Independence
The two-stage approach (generate index → validate references) makes it adaptable to any traffic information format, including DATEX II, RDS-TMC, legacy national formats, or custom implementations.
Operational Efficiency
Automates validation that would otherwise require manual checking of thousands of location references.
Compliance
Ensures conformance with ISO/DIS 14819 standard for ALERT-C location tables.
Reusability
While developed for Czech use case, the tool can work with any country's ALERT-C location tables in standard TMC format.
Community & Contributions
The maintainers welcome community contributions:
- New location indices: Contributors can add indices for additional countries
- Format adapters: Implementations for extracting references from different formats
- Improvements: Bug fixes, feature enhancements, documentation
- Issues: Report problems or suggest improvements on GitHub
Community Extensible
If you have properly licensed ALERT-C location tables for your country, consider contributing the generated indices to help the wider community!
Getting Started
Prerequisites
- Python 3.x
- TMC location tables for your country (.DAT format)
Installation
git clone https://github.com/tamtamresearch/alert-c-locations-tester.git
cd alert-c-locations-tester
pip install -r requirements.txtBasic Usage
Generate location index:
bashinv generate-index --location-table=your-table.DATImplement reference extraction for your format (use DDR.xml example as template)
Validate your traffic data:
bashinv validate --content=your-traffic-data.xmlReview results: Check output for invalid location references
Related Tools
This tool complements other DATEX II and traffic information tools:
- DATEX II Browser - For exploring DATEX II model
- DATEX II Schema Tool - For creating DATEX II profiles
- Validators for DATEX II content (coming soon to catalog)
Support
- Issues: GitHub Issues
- Source Code: GitHub Repository
- Documentation: Included in repository