ISO 20383:2025

Tractors and machinery for agriculture — Speed Identification Sign (SIS)

This document specifies the dimensions, characteristics, and positioning of Speed Identification Signs (SIS). These signs indicate the maximum equipment ground speed, based on the ground speed design capability, for agricultural field equipment. This document is applicable to agricultural field equipment moving on public roads.

Tracteurs et matériels agricoles et forestiers — Signe d'identification de la vitesse (SIV)

L'ISO 20383 :2017 spécifie les dimensions, les caractéristiques et le positionnement des Signes d'Identification de la Vitesse (SIV). Ces signes indiquent la vitesse au sol maximale du matériel sur la base de la vitesse au sol maximale possible de conception pour un véhicule agricole. Un SIV orienté vers l'arrière est visible pour les autres utilisateurs des voies publiques s'approchant de l'arrière du matériel. Un SIV monté à l'avant d'un matériel remorqué averti les opérateurs du véhicule de remorquage de la vitesse au sol maximale possible spécifiée à laquelle l'ensemble de matériels peut être utilisé. L'ISO 20383 :2017 s'applique aux équipements automoteurs, semi-portés et remorqués se déplaçant sur les voies publiques.

General Information

• Status: Published
• Publication Date: 07-Oct-2025
• ICS: 65.060.10 - Agricultural tractors and trailed vehicles
• Technical Committee: ISO/TC 23/SC 4 - Tractors
• Drafting Committee: ISO/TC 23/SC 4 - Tractors
• Current Stage: 6060 - International Standard published
• Start Date: 08-Oct-2025
• Due Date: 09-Jul-2026
• Completion Date: 08-Oct-2025

Relations

• Revises: ISO 20383:2017 - Tractors and machinery for agriculture and forestry — Speed Identification Sign (SIS)
• Effective Date: 27-Jul-2024

Standards Content (Sample)

International
Standard
ISO 20383
Second edition
Tractors and machinery for
2025-10
agriculture — Speed Identification
Sign (SIS)
Tracteurs et matériels agricoles et forestiers — Signe
d'identification de la vitesse (SIV)
Reference number
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
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or ISO’s member body in the country of the requester.
ISO copyright office
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Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3  Terms and definitions . 1
4 Dimensions . 2
5 Materials, performance and test requirements . 3
5.1 Performance requirements .3
5.2 Adhesion .3
5.3 Colour measurement .3
6 Positioning . . 3
6.1 Rear facing SIS .3
6.2 Forward facing SIS .4
6.3 Towed equipment combinations .4
7 Operating instructions for towing vehicles . 4
Bibliography . 6

iii
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
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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).
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This document was prepared by Technical Committee ISO/TC 23, Tractors and machinery for agriculture and
forestry, Subcommittee SC 4, Tractors.
This second edition cancels and replaces the first edition (ISO 20383:2017), which has been technically
revised.
The main changes are as follows.
— The term “forestry” was removed from the title.
— In the introduction, the term “implement of husbandry/agricultural equipment” has been replaced with
the term “agricultural field equipment” as defined in ISO 12934.
— In the last sentence of Clause “1 Scope” the list of terms “self-propelled, semi-integral and towed
equipment has been replaced with “agricultural field equipment” as defined in ISO 12934.
— In Clause 1, subclause 6.1.1 and subclause 6.1.3, the term “agricultural vehicle” has been replaced with
“agricultural field equipment” as defined in ISO 12934.
— In 3.2, the definition of “implement of husbandry” has been replaced with the definition of “agricultural
field equipment” according to ISO 12934.
— In Figure 1 of subclause 4.1, the depiction of the symmetrical tolerance has been corrected according to
ISO 129-1.
— In 4.4, the explanation in parenthesis "(e.g. 45 to 50)" has been corrected to "(e.g. 40, 45, 50)".
— ISO 12934 has been added to the Bibiliography.
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.

iv
Introduction
Agricultural field equipment operations include the transport of commodities and equipment from the field
sites to farmsteads, storage facilities and gathering points for movement by mass transit systems. Equipment
often moves between farmsteads and field sites that are not contiguous. Transport may involve moving on
public roads (infrastructure) that permit faster ground speeds than that which is used in the fields or within
the design considerations of the equipment. Design approaches have been identified to permit selected
equipment to move at faster ground speeds in transport configurations. This doc
...