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Technical Note – Curved Guardrail at an intersection with a minor road
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The New Zealand Transport Agency (NZTA) has prepared a drawing detailing the correct layout and configuration of a curved terminal installation at the intersection with a minor road.  This drawing covers all new installations and maintenance situations.

The memo and drawing will soon be available from the NZTA website. If you have any enquiries regarding these details please contact the National Traffic & Safety Engineer, Highways & Network Operations, NZTA National Office or

The main points of this drawing are as follows:

  • Covers non-proprietary strong post timber W-Beam guardrail system only
  • A curved trailing terminal is to be installed only on a low speed, low volume road. For a high speed, high volume road the terminal must be NZTA Specification M23 Appendix ‘A’ compliant
  • Minimum clear zone of 22m x 6m to be provided behind the guardrail
  • The rail rests on a shelf angle at the apex of the curve with no bolt through the rail
  • There can be up to three apex posts depending on the most likely vehicle impact direction

Note that only a strong post timber W-Beam guardrail system may be installed in this situation, proprietary guardrail systems cannot be used at this time.

View technical drawing >

Auckland, Northland and Central North Island Lower Nth Island Sth Island