The Austroads Guide to Road Design is the Waka Kotahi NZ Transport Agency's primary source of guidance for the design of the highway network. However, there are some important New Zealand specific variations and interpretations that reflect our unique terrain, driving conditions and road rules.

Superelevation calculations (TM2501)

Published: August 2021

Technical memorandum TM2501 Superelevation calculations, provides information for practitioners on the calculation of road superelevation appropriate for a vehicle speed and curve radius. This is consistent with the SHGDM chapter 2: basic criteria.

TM2501 Superelevation calculations

State highway geometric design manual: Chapter 2: Basic criteria 

This information should be used in place of that given in the Austroads Guide to Road Design Part 3 Section 7.7.1.

Calculating road surface water run-off (TM2502) 

Published: August 2021

Technical Memorandum TM2502 Preferred method for calculating road surface water run-off in New Zealand, provides advice on the preferred method of calculating surface water flow and the limited use of the Gallaway method in New Zealand.

January 2014 update: This update highlights an error in the formula on page 3 of the original document Highway surface drainage: A design guide for highways with a positive collection system and quotes the correct formula.

TM2502 Preferred method for calculating road surface water run-off in New Zealand

State highway geometric design manual (SHGDM)

Published: December 2000

The primary source of design guidelines for the State Highway Network is the Austroads Guide to Road Design 2009. However, the State highway geometric design manual (2000) may be an important reference document for some projects, depending on their context and the stage in their life-cycle.

State highway geometric design manual

Safe system guidelines for RoNS (TM2503)

Published: March 2013

The launches of the Safer Journey's initiative and the Decade of Action for Road Safety have brought the way we design for safety into the limelight. Technical Memorandum TM-2503, Guidelines for edge protection and medians on dual carriageway roads, incorporating a Safe System philosophy, defines the interpretation of a Safe System philosophy for dual carriageways, including the RoNS projects and how this may vary with context.

Decade of Action for Road Safety(external link)

TM-2503, Guidelines for edge protection and medians on dual carriageway roads, incorporating a Safe System philosophy

Appendices to this memorandum provide examples of the rationale in practice, an analysis of the benefits and costs and also typical sections that illustrate these principles.