ALERT-C Locations Tester

[vlcinsky]

Tool Information

Name: ALERT-C Locations Tester

Description:
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 Part 3), providing complete enumeration of all possible location references for a given version of location tables.

To test location references, users must extract them from actual traffic information content (the repository contains an example implementation for legacy Czech format DDR.xml). By comparing extracted values with the location index file, the tool detects references that should not be used.

Examples of invalid location references detected by the tool include:

• Extent values above 31 (maximum allowed is 31)
• Non-existent primary location codes (e.g., location code 0)
• Invalid combinations of primary location, direction, and extent
• References to locations not defined in the location table version

Link:
https://github.com/tamtamresearch/alert-c-locations-tester

Standards Supported:

• DATEX II (applicable for road traffic information content using ALERT-C)
• NeTEx
• SIRI
• GTFS
• TN-ITS
• Other: ISO/DIS 14819 Part 3 (ALERT-C location tables in TMC format), RDS-TMC

Tool Type:

• Validator
• Converter/Transformer
• Library/SDK
• Reference Implementation
• Development Tool
• Documentation Generator
• Other: Data Quality Assurance

License:
MIT

Maintenance Status:

• Actively maintained (last updated October 2025)
• Stable/Mature (infrequent updates)
• Not actively maintained but working
• Unknown

Technology Stack:

• Python
• SQLite
• Command-line tool using Invoke package

Additional Context:

• Processes TMC location tables (.DAT files) conforming to ISO/DIS 14819 Part 3 standard
• Generates location indices as SQLite databases and CSV files for efficient validation
• Currently includes location reference indices for Czech location tables
• Format-agnostic validation: works with any traffic information format once location references are extracted
• Repository includes reference implementation for DDR.xml (legacy Czech format)
• Adaptable to DATEX II and other traffic information formats
• Can handle large location tables (example shows 45,929 allocated locations)
• Validates three key components: primary location codes, directionality (+/-), and extent values (0-31)
• Initial development funded by Ředitelství silnic a dálnic s.p. (Czech Road and Motorway Directorate)
• Currently in operational use by Czech Road and Motorway Directorate (ŘSD)
• Community contributions welcome: new country location tables can be added if provided with proper licensing

Location Table Availability:
ALERT-C location tables are not included in the repository due to licensing restrictions. However, they are typically available from national traffic information centers. For example, Czech location tables can be obtained for free after signing a license agreement at: https://registr.dopravniinfo.cz/en/sources/cz-ndic_tmc-location-table-v11.0/

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Why Include This Tool?

This tool addresses a critical data quality challenge in road traffic information systems using ALERT-C location referencing, which is widely used across Europe for RDS-TMC broadcasts and increasingly for DATEX II traffic information exchange.

Value proposition:

• Data Quality Assurance: Systematic validation prevents broadcasting incorrect location information that could mislead drivers and compromise road safety
• Compliance Verification: Ensures conformance with ISO/DIS 14819 Part 3 standard for ALERT-C location tables
• Format Independence: The tool's 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
• European Relevance: ALERT-C is widely used for road traffic location referencing across Europe, both in traditional RDS-TMC and modern DATEX II services
• Reusability: While developed for Czech use case, the tool can work with any country's ALERT-C location tables in standard TMC format
• Production Proven: Already in operational use by national road infrastructure authority
• Open Source: MIT licensed, allowing adoption and adaptation by other National Access Points and traffic information providers
• Community Extensible: Maintainers welcome contributions of location indices for additional countries

The tool is particularly relevant for:

• Organizations operating RDS-TMC services across Europe
• National Access Points managing DATEX II traffic information feeds with ALERT-C location referencing
• Traffic information service providers needing to validate location data quality
• Any entity working with ISO/DIS 14819 Part 3 compliant location tables