Engineering students are required to find a public works report from the Appendices to the Journals (shelved on Level 3 in the NZ Govt Pubs collection). Find the cumulative index volumes for the A-Js (helpfully shelved after the 1906 volumes) and look up Public Works to find a list of entries about bridges, roads, viaducts etc.
Alternatively most of the public works reports are in section D of the volumes. You might need to go up to the shelves with the students.
I was so pleased to be able to access this posting, thank you Janette. We had a borrower come to the Desk with precisely this question and we were able to provide the answer in a very expert manner!