Overview
ISO 17387:2008 - Intelligent transport systems - Lane change decision aid systems (LCDAS) - specifies performance requirements and test procedures for Lane Change Decision Aid Systems (LCDAS). The standard covers LCDAS intended to warn drivers of potential collisions with vehicles to the side and/or rear while changing lanes. It applies to forward-moving cars, vans and straight trucks in highway situations and explicitly excludes motorcycles and articulated vehicles. ISO 17387 clarifies system scope: LCDAS supplements mirrors, does not take control of the vehicle, and responsibility for safe operation remains with the driver.
Key topics and technical requirements
- System classification
- Type I: Blind spot warning (adjacent zones).
- Type II: Closing vehicle warning (rear zones).
- Type III: Full lane change warning (adjacent + rear).
- Target vehicle closing speed classes (affect sensor range and acquisition time):
- Type A: up to 10 m/s (min curve radius 125 m)
- Type B: up to 15 m/s (min curve radius 250 m)
- Type C: up to 20 m/s (min curve radius 500 m)
- Coverage zones and definitions: left/right adjacent zones; left/right rear zones; lateral and rear clearance; closing speed; time-to-collision.
- Functional requirements
- State diagram for LCDAS behavior, detection and warning criteria.
- User interface expectations for timely, interpretable warnings.
- Self-test and fault indication requirements.
- Operation considerations for trailers.
- Test methods
- Test target vehicle definitions, environmental conditions.
- Specific test procedures for blind spot warning, closing vehicle warning, and lane change warning performance.
- Informative example cases and measurable pass/fail criteria.
Applications and who uses this standard
- OEMs and Tier-1 suppliers developing ADAS, blind spot detection, and lane-change aids will use ISO 17387 to design systems that meet harmonized performance and test expectations.
- Sensor and software vendors (radar, lidar, camera, fusion algorithms) to define sensor range, acquisition time and detection zones.
- Test labs and certification bodies for validating LCDAS against defined procedures and environmental conditions.
- Regulators and safety engineers to reference standard performance levels when shaping policy or vehicle safety requirements.
- Researchers studying human–machine interaction and lane-change safety performance.
Related standards and context
ISO 17387 was prepared by ISO/TC 204 (Intelligent transport systems) and is part of the broader ITS/vehicle-safety standards landscape. Manufacturers typically use it alongside other vehicle safety and ADAS standards when specifying, testing and documenting lane-change assistance functions.
Keywords: ISO 17387, LCDAS, Lane Change Decision Aid Systems, intelligent transport systems, blind spot warning, closing vehicle warning, lane change warning, performance requirements, test procedures.