Holidaymakers leaving Auckland for the long weekend were held up for more than an hour while roadworkers repaired a main route out of the city.

The Victoria Park flyover, which takes State Highway 1 through the central city, was reduced to one lane in each direction between 11.30am and 2pm, causing 10km tailbacks.

Susan Holmes left Birkenhead at 12.45pm, heading to Taupo. It took her an hour to get to Cook St, about 8km away.

New Zealand Transport Agency spokesman Tommy Parker said parts of the road were sinking due to rain and water used to clean up work done to the drainage system.

"We wouldn't want to be putting anyone at risk by not having done the work because it was a long weekend."