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Geometric design

The Transport Agency use the Austroads guide to road design as the primary reference guideline for our road network. Links to the Austroads(external link) guides and supplementary guidance are available on the Geometric design page of the NZ Transport Agency website. The Geometric design page provides advice about the use of the guide and supplementary information for practitioners as projects transition from the previous guidelines through their life-cycle. It also provides additional policy and design advice on road construction industry related issues.

Manuals and memoranda

Superelevation calculations technical memorandum (TM2501) (2012)

This memorandum provides information for practitioners on the calculation of road superelevation appropriate for a vehicle speed and curve radius. It is consistent with the SHGDM chapter 2 – basic criteria. Note: 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 technical memorandum (TM2502) (2012)

This memorandum details the preferred method for calculating road surface water run-off in New Zealand. It also provides advice on the preferred method of calculating surface water flow and the limited use of the Gallaway method in New Zealand.

State highway geometric design manual (SHGDM) (2005)

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) remains the primary reference document for some projects, depending on the stage in their life-cycle.

Guidelines for edge protection and medians on dual carriageway roads, incorporating a Safe System philosophy (TM2503) (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. This guide incorporates a Safe System philosophy and defines the interpretation of a Safe System philosophy for dual carriageways and RoNS projects.

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

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