Delays of up to 12 minutes are possible at the Maungatapu roundabout on state Highway 29a this weekend.
The NZ Transport Agency encouraged drivers to avoid the area.
Heavy machinery, including large cranes, would be moving a high voltage power line so work could continue on the roundabout as part of the Maungatapu underpass project.
Speed restrictions and lane closures would be in place on Saturday July 30 and Sunday July 31 between 7am and 6pm.
Motorists driving through the area could experience lengthy delays and have been urged to use alternative routes or plan travel outside the hours to avoid delays at the busy work site.