One of the main roads to Coromandel's beach towns has been closed due to numerous large cracks appearing in the road, with no guarantee it will reopen for the upcoming long weekends.

Waka Kotahi says they made the decision to close SH25A road on Monday after cracks were identified and the potential risk of them worsening overnight.

Regional Manager for Maintenance and Operations, Rob Campbell says geotechnical investigation on Tuesday will decide if the road will remain closed or can safely reopen.

'The cracks have appeared following Cyclone Hale, which caused flooding and numerous slips across the Coromandel Peninsula. As there are numerous cracks we need to understand what is happening before we allow road users through this area.”

He used SH32 near the Motu River in the Eastern Bay of Plenty as an example where the situation moved rapidly and lost a lane to the river within days of the first cracks appearing.

'While that may not happen here, we cannot take any chances.”

State Highway 25A is one of the major routes to Coromandel's holiday hotspots. Image: Google Maps.

Campbell did say it is too early to say whether the road will remain closed over the upcoming long weekends, with Auckland Anniversary the January 28 – 30 and then Waitangi weekend the following week.

With SH25A closed, road users will need to use SH2 through the Karangahake Gorge or SH 25 around the Coromandel Peninsula to travel to/from summer hotspots such as Whitianga and Whangamatā.

'The alternative routes will add at least half an hour to travel times. With temperatures rising and sunny days on the horizon, fatigue can set in earlier than usual.”

Further updates will be provided when more information is available.