ISO 23793-1:2024

Overview - ISO 23793-1:2024 (Intelligent transport systems, MRM)

ISO 23793-1:2024 defines a framework and minimum requirements for Minimal Risk Manoeuvres (MRM) performed by Automated Driving Systems (ADS). It covers the classification of MRM types, the decision-making principles for selecting an appropriate MRM, and the control strategy and test procedures for the two simplest MRM types: straight stop (type 1) and in-lane stop (type 2). The standard applies to light‑duty vehicles equipped with Level 3–5 ADS and addresses MRM performance from initiation to termination with the objective of reaching a Minimal Risk Condition (MRC). It does not cover detection methods that trigger MRMs nor detailed system-level safety design requirements (see Related Standards).

Key topics and technical requirements

• MRM classification framework: concept of MRM operation, types (traffic-lane stop vs road-shoulder stop), and allowed type changes.
• Function/state model: state diagram for ADS active, MRM initiation, MRC, sustained standstill, and manual driving transitions.
• Decision-making principles: rules for selecting MRM type based on vehicle state and traffic context (high-level, not prescriptive algorithms).
• Minimum control strategy requirements for the two basic MRMs:
  • Straight stop: requirements for deceleration control, lateral stability, detection capability and safe stopping location.
  • In-lane stop: operational speed limits, longitudinal control, lateral control tolerance, and MRC positioning.
• Operational constraints: monitoring of vehicle/ADS status, triggering conditions, operational speed during MRM, and failure mitigation strategy.
• Standstill and resumption: requirements for sustained standstill management and procedures to resume operation after an MRC.
• Performance evaluation and test methods: test conditions, vehicle/test-course setup, basic MRM function tests, and human-user takeover tests.
• Interface and information: internal/external status reporting during MRM (e.g., HMI and external signals).

Applications - who uses ISO 23793-1

• ADS developers and system architects defining fallback behaviors and MRM logic.
• OEMs and vehicle integrators implementing Level 3–5 automated driving functions.
• Test laboratories and validation teams creating MRM performance test procedures.
• Regulators, certification bodies, and compliance engineers evaluating ADS minimal‑risk behavior.
• Safety and assurance teams aligning operational requirements with formal test methods.

Related standards

• ISO 26262 - Functional safety of electrical/electronic systems (MRM design considerations out of scope here).
• ISO 21448 (SOTIF) - Safety of the intended functionality.
• ISO/TS 23792-1 - Motorway chauffeur systems (related ADS context).
• ISO 22737 - Low speed automated driving (LSAD) systems.
• ISO/SAE PAS 22736 - Minimal risk condition (MRC) concepts referenced in the introduction.

For implementation or procurement, obtain the full text from ISO (iso.org) to use the precise normative language and test procedures defined in ISO 23793-1:2024.