The Waikato Expressway will provide 102km of continuous divided four-lane highway and cut SH1 by 6km. It will provide a further 12km of new or upgraded links and a new bridge over the Waikato River north of Hamilton.
It will join up with the existing SH1 south of Cambridge and will cut travel times between Auckland and Tirau by 35 minutes. Its estimated completion date is 2019. Herewith an overall view (bearing in mind this was last July, the most recent summary I could find):
* Pokeno and Mercer sections totalling 22.6km are completed.
* Longswamp section and Rangiriri section totalling 10.3km have been investigated and designed, and enabling works on Rangiriri (archaeology and Transpower relocation) is in progress.
* 7km Ohinewai section completed.
* 15.2km Huntly section in secondary investigation and specimen design.
* 12.3km Ngaruawahia section now in the construction phase with the contract awarded in March. Main construction work started in last spring.
* Te Rapa section of 7.3km is under construction and is due for completion in December.
* Hamilton section of 21.8km is now being investigated and designed.
* 2.4km Tamahere interchange done.
* Tamahere section of 4.4km is now under investigation with design to follow.
* Cambridge section of 10.4km is being designed.
It appears, from what I have been able to glean, that the new road will run east of Taupiri Mountain, to reduce impact on sacred sites.