National foreword

This British Standard is the UK implementation of ISO 23375:2026. It supersedes BS ISO 23375:2023, which is withdrawn.

The UK participation in its preparation was entrusted to Technical Committee EPL/278, Intelligent transport systems.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 November 2026.

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO document should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

ISO draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s) which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 204, Intelligent transport systems.

This second edition cancels and replaces the first edition (ISO 23375:2023), which has been technically revised.

The main changes are as follows:

extended with performance requirements and test procedures for a type of automatic collision evasive lateral manoeuvre system (CELM) that permits lane crossing under specified conditions;
included performance requirements and a test procedure for the original heading angle adjustment function for a type of driver‑initiated CELM.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

Introduction

Reducing traffic fatalities, injuries and property damage caused by driver carelessness or unexpected events is a global challenge. To address this situation, automatic emergency braking (AEB) systems were introduced to mitigate crash consequences through automatic deceleration by braking of the vehicle.

NOTE ISO 22839 and ISO 19237 are examples of related International Standards defining the minimum performance requirements of such systems. The ISO 22733 series defines test procedures to evaluate the performance level of such systems.

These AEB systems work effectively when there is a high probability of a collision, but their operation can be limited, or they can potentially not work at all, when there is a low probability of a collision (e.g. when the degree of overlap to the object is small). However, even in such scenarios, there are cases where a collision can be avoided by system support, i.e. by a small amount of lateral movement.

This document defines functional requirements, minimum performance requirements and test procedures to verify these requirements for collision avoidance systems using lateral movement of the vehicle, i.e. a collision evasive lateral manoeuvre system (CELM).

A CELM is a safety system aimed at supporting the driver’s vehicle operation by avoiding collisions with objects in the forward path of the vehicle. When a collision is predicted, the CELM controls lateral movement of the vehicle by generating yaw moment.

The lateral control manoeuvres can be performed automatically by CELM or can be initiated by the driver and supported by CELM.

1 Scope

This document specifies basic control strategies, minimum functional requirements, basic driver interface elements, and test procedures for verifying the system requirements for collision evasive lateral manoeuvre systems (CELM).

Specific methods for object detection and other environmental perception technologies are not described in this document.

This document applies to light vehicles^[1^] and heavy trucks^[1^]. Vehicles equipped with trailers are not within the scope of this document.

2 Normative references

3 Terms and definitions

4 Symbols and abbreviated terms

4.1 Symbols

4.2 Abbreviated terms

5 System overview

5.1 General

5.2 Classification

6 General functional requirements

6.1 Functional elements

6.2 State transition

6.3 Response to failure during CELM active state

6.4 Status indication

6.5 Status symbols

6.6 Minimization of vehicle lateral movement by CELM

6.7 Driver override

6.8 User-adjustable intervention thresholds

6.9 Information to the user in the manual

7 Operating conditions and requirements for Type 1 systems

7.1 General

7.2 Object condition

7.3 Activation speed of subject vehicle

7.4 Road condition

7.5 Operational limit

7.6 Additional operating conditions and requirements for CELM Type 1-B, when crossing lane markings

8 Operating conditions and requirements for Type 2 systems

8.1 General

8.2 Object condition

8.3 Activation speed of subject vehicle

8.4 Adjustment to the original heading angle after avoiding a collision

9 Performance evaluation test methods

9.1 General

9.2 Test conditions

9.3 Type 1 test procedures

9.4 Additional Type 1-B Test procedures

9.5 Type 2 test procedures

Bibliography