Delays of up to an hour have been experienced by motorists travelling along SH2 between Waihī and Tauranga this week.
Public holidays, students starting back at school and people are returning to work all contributed to the increased traffic.
Other reasons included summer road works and project activity.
A spokesperson for NZTA said this was expected to continue for several weeks, especially as the road maintenance crews took advantage of settled weather.
There would be an increased number of worksites over the next month, including 20 chipseal sites between Bethlehem and Athenree.