CONTACT CENTRE WAIT TIMES: Our Contact Centre is currently experiencing significant wait times. View frequently asked questions

SCAM ALERTS: Report a phishing scam or learn about the latest phishing emails

ROAD USER CHARGES (RUC) DISCOUNT: Find out more about the temporary RUC reduction scheme

ONLINE SERVICES: We are currently experiencing issues with all our online services at the moment. We are working to resolve the services as soon as possible. We apologise for any inconvenience caused.

COVID-19 SERVICES UPDATE: Information on Waka Kotahi services, extensions and more

ONLINE SERVICES: We currently have an issue with receiving some payments and are working to resolve this issue as quickly as possible. We apologise for any inconvenience.

EASTER WEEKEND – PLAN AHEAD: Heading away for the long weekend? Check our holiday journeys tool(external link)

SCAM ALERTS: Refund email and Vehicle licence (rego) renewal phishing emails


Back to Resources

#22-05 Update to M23 Specification & Guidelines for Road Safety Hardware

Published: | Category: Technical advice note | Audiences: Road controlling authorities, Road traffic engineers & consultants, Roading contractors

This note is to advise that M23 Specification & Guidelines for Road Safety Hardware has been updated. The new document M23:2022 applies from the date of this notice.

Publication details


This note is to advise that M23 Specification & Guidelines for Road Safety Hardware has been updated. The new document M23:2022 applies from the date of this notice.

General information

M23:2022 Specification & Guidelines for Road Safety Hardware is intended to be used by Waka Kotahi, other Road Authorities, Installation Designers and System Installers when designing, specifying, installing, and maintaining road safety hardware.

The guidance outlined in this document should be followed by those working on Waka Kotahi projects incorporating safety hardware from now on.

Purpose of the change

The current M23:2009 refers to testing standards and best practice guidance that have been superseded since its release. Interim updates to M23 have been released to address industry changes and gaps in guidance that result in frequently asked questions, however this has resulted in many separate documents making up the specification. The revised document refers to the latest testing standard and best practice guidance and incorporates other guidance previously promulgated in one package.

Specific changes

The changes to M23 include:

  • adoption of the American Association of State Highway and Transportation Officials Manual for Assessing Safety Hardware (MASH) testing protocol
  • adoption of the updated New Zealand and Australia Standard AS/NZS 3845.1 and 3845.2 (2015 and 2017 respectively)
  • alignment with the updated Austroads Guide to Road Design Part 6: Roadside Design, Safety and Barriers (Austroads Part 6)
  • guidance information developed and promulgated since the previous revision
  • best practise and alignment with like documents
  • incorporation of the previous M23:2009 Notes within the document
  • the addition of appendices A to G for specific details.

Communication plan

Our target audience for this document is all practitioners working with road safety hardware.  Advice of these changes will be promulgated by:

  • this note advising the document’s release
  • direct access via the Waka Kotahi website and intranet
  • communication via the REG channels and RCA forum
  • an email to practitioners known to be working with road safety hardware
  • creation of email to aid resolution of queries.


M23:2022 Specification & Guidelines for Road Safety Hardware is published for use on the Waka Kotahi website, including the updated lists of approved products.

Road safety barrier systems (NZTA M23:2022)(external link)

Only approved products may be used on Waka Kotahi projects from now on and this requirement will be monitored.

Document review

Assessment of the effectiveness of the changes will be monitored by interactions with project personnel and the ‘M23.Queries’ emails, with a formal review to be undertaken in April 2023. Document appendices will be updated as required, which, in the case of appendices featuring details of accepted products, will be around quarterly.

Publication details

Publication: Road safety barrier systems (NZTA M23:2022)
Author: Waka Kotahi NZ Transport Agency
Published: May 2022
Reference: M23:2022 Specification & Guidelines for Road Safety Hardware document
Version: 5

Further information

If you have any questions or feedback, please contact the Road Safety team at 



Greg Haldane
Chair, Ratification Group

Vanessa Browne
Delegated Approver