Overview
ISO/TR 21959-1:2020 - "Road vehicles - Human performance and state in the context of automated driving - Part 1: Common underlying concepts" provides a harmonized set of informative concepts describing driver performance and driver state for automated driving. It applies primarily to systems that require a human to remain engaged or fallback-ready (notably SAE levels 1, 2 and 3) and can also inform features that allow the driver to resume manual control across SAE levels 1–5. The report is intended for researchers, OEMs, human factors practitioners and test engineers and is applicable across vehicle categories and test contexts (driving simulators, test tracks, public roads).
Key topics and technical concepts
- Transition process models - conceptual models for transitions from manual → automated driving and automated → manual driving, including system- and driver-initiated transitions.
- Definitions of driver states and activities - clear terminology for concepts such as Manual Control, Automation Available, Activation/Request to Engage Automation, and Automated Driving.
- Driver state transition - physical and cognitive aspects of releasing control to automation and of regaining control from automation (hands/feet release, cognitive confirmation).
- Measures for human performance - topics and candidate measures for assessing transition performance (behavioural markers, timing, success/failure indicators) - presented as guidance rather than prescriptive requirements.
- Mental and non-driving related states - taxonomy of mental states, Non-Driving Related Activities (NDRA) and Non-Driving Related Tasks (NDRT), posture and driving position considerations.
- Driver readiness / availability - concepts that predict intervention performance and are relevant to driver monitoring and system HMI.
- User experience factors - prior system image, education and training, user understanding of driving automation, and behavioral attitudes while using the system.
Note: ISO/TR 21959-1:2020 is informative (technical report) - it provides consensus guidance where available and highlights research gaps rather than setting normative requirements.
Practical applications - who uses it
- Automotive OEMs and Tier-1 suppliers for concept alignment and product descriptions
- HMI designers and UX teams to evaluate driver understanding and handover cues
- Human factors researchers designing simulator and on-road evaluations
- Test engineers planning restricted-road or public-road trials
- Regulators and safety assessors seeking common terminology for driver-related evaluations
- Technical writers preparing owner manuals and product documentation
Related standards
- SAE J3016 (levels of driving automation) - referenced for automation level definitions
- SAE J3114 - complementary guidance on automated driving concepts
- ISO/SAE 22736 (planned) - expected to cover additional aspects referenced in this report
- Other parts of the ISO 21959 series for more detailed or normative guidance
Keywords: ISO/TR 21959-1:2020, automated driving, human performance, driver state, SAE levels, driver readiness, HMI, driver monitoring, NDRA, NDRT, human factors.