NZTA has been publishing their research reports on their website for the last few years, and this online resource is rather valuable. Older research reports were previously only available for purchase. Just in case you didn't see it, they stated the following in their latest NZTA research newsletter:
"PDF scans of research reports published prior to 2005 are available by emailing email@example.com"
We have added the scan of Research Report 230 to our website.