No further details will be released until his next of kin have been notified.
The truck driver was shaken but not hurt.
The road is likely to remain closed for some hours and diversions are in place at SH27 and SH29.
The area of SH1 and SH29 has been dubbed a "high-risk rural intersection" by the New Zealand Transport Agency and is one of two Waikato intersections set to be turned into a roundabout later this year.
The work, part of NZTA's $1.821 billion investment into the Waikato transport network announced last month, is aimed to be completed by summer with tenders going out in the next few months.
NZTA's acting Waikato/Bay of Plenty regional director, Robert Brodnax, said in its earlier announcement that significant investments will also be made in motorcycle safety in the region, with safety initiatives planned for some of the most popular motorcycle touring routes; the northern Coromandel loop and, in partnership with Waikato District, the Tuakau to Raglan road [the old route 22].
The SH3/SH21 intersection, adjacent to Hamilton airport, is the other major intersection to be transformed into a roundabout.