Motorists can expect major delays on the Crown Range on Tuesday 31 January as upgrade work on the road continues.

Queenstown Lakes District Council project manager Rob Darby said the delays would take place between 10am and 2pm and were expected to last up to an hour.

"The long delays are necessary to allow stabilisation work of the road surface to take place," he said.

"Anyone planning a journey over the Crown Range during that time should either allow for an extra hour or use State Highway 6 and travel via Cromwell."

Mr Darby said signage advising of the delays and the alternative route would be posted at either end of the Crown Range.

The Crown Range/Cardrona upgrade is scheduled to be completed by the end of April.