Mr Grace said there were now several investigations underway, with WorkSafe NZ and the police serious crash and commercial vehicle investigation units looking into the fatality.
"At this point in time it is too early to comment on other factors related to the crash but what we can say is this is the 10th fatality on Waikato roads this year, and police are urging all road users to exercise caution on their travels, particularly in areas controlled by temporary speed restrictions."
Police were warning motorists to expect delays in the area, and a rural road linking State Highway 1 and SH2 would be closed for several hours this afternoon.