A section of State Highway 2 in Tauranga will be reduced to one lane tomorrow.

Core sample testing will be conducted in each lane of SH2, between Waihi and Bethlehem roads, says the NZTA.

"One lane will be availiable at all times.

"Contraflow will be in place with a 50Km/h in place."

The works are expected to be completed by 6am on Friday, May 31.