Part of Harrington Sound Road will be reduced to one lane of traffic so workers can investigate a hole in the asphalt surface.

The Ministry of Public Works and Environment said the emergency closure is in already in effect in the eastbound lane, up the hill from Shark Hole.

Investigation work will take place from 7.30am to 3pm and traffic is being controlled with signs and lights.

A spokesman said: “Motorists are urged to exercise caution when travelling along Harrington Sound Road, both day and night, and to expect delays during the investigation period.”

Drivers should detour via North Shore Road to minimise disruptions.

The ministry apologised for any inconvenience that may result as workers improve road safety.

Questions should be directed to principal highways engineer Tina Beer-Searle on 504-3044.