Overview
ISO/PAS 11585:2023 - "Road vehicles - Partial driving automation - Technical characteristics of conditional hands-free driving systems" defines the system-level technical characteristics and control strategies for L2 hands-free partial driving automation. It specifies how a supervised partial automation system may permit drivers to remove hands from the steering wheel within an appropriate operational design domain (ODD). The specification focuses on functional states, transitions and minimum subsystem requirements; it does not address performance limits, verification or validation.
Key topics and technical requirements
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Scope and applicability
- Targets partial driving automation systems in passenger cars (L2 hands-free); excludes Level 3+ automated driving systems.
- Aligns with ISO/SAE PAS 22736 system definitions; region-specific regulation (e.g. UN/ECE R79) may affect applicability.
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System states, modes and transitions
- Defines the L2 hands-free state and its transitions to/from manual driving, PADS active (ISO 21717) and other modes.
- Describes triggers for entering/exiting hands-free, including driver or system interventions and risk-mitigation exits.
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Control strategy and control loop
- Specifies the overall control context (longitudinal and lateral control coordination) in combination with ACC (ISO 15622) and PADS (ISO 21717).
- Clarifies driver actions: overrule (deactivate system), override (direct control within thresholds).
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Driver-monitoring and interface
- Requires a driver-monitoring system (DMS) to assess driver attention and hands-on/off detection; typical implementation includes a driver-monitoring camera (DMC) and capacitive steering-wheel detection.
- Defines driver information and warning elements: eyes-on request (EOR), hands-on warning (HOW) and hands-on alert (HOA) with visual/acoustic cues.
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Subsystem characteristics
- Technical characteristics for key subsystems: DMS, driver information/warning system, ODD-monitoring system, and risk-mitigation system.
- Specifies minimum behavioral requirements for ODD monitoring and responses when ODD or driver conditions change.
Practical applications and users
- Useful for:
- Automotive OEMs and subsystem suppliers designing L2 hands-free features.
- AD system architects integrating ACC/PADS with driver monitoring.
- Regulators and safety assessors seeking standardized functional descriptions and expected behaviours.
- Test labs and technical writers preparing requirements and user-facing documentation.
- Enables consistent implementation of hands-free driving modes, driver warnings, transition behavior, and ODD monitoring to improve safety and usability.
Related standards
- ISO/SAE PAS 22736 (system definitions for partial automation)
- ISO 15622 (Adaptive Cruise Control - ACC)
- ISO 21717 (PADS - Partial Driving Automation Driver Support)
- Regional regulation example: UN/ECE R79
Keywords: ISO/PAS 11585:2023, L2 hands-free, partial driving automation, driver-monitoring system, ODD monitoring, driver information and warning, PADS, ACC.