People heading to the Coromandel for their long weekends should expect a slower journey across the base of the peninsula.

Cracks in SH25A between Kōpū and Hikuai mean one lane of the road will be open during daylight hours, under stop-go and with a 30kmh speed limit.

The cracks are believed to be a Cyclone Hale remnant and the road was temporarily closed last week while they were investigated.

It was reopened on Wednesday but is 'still seeing active movement” and there's no end in sight for the current traffic management as the transport agency investigates.

There have already been reports of 'unacceptable” behaviour towards crews manning the closures, Waka Kotahi says.

While this may be disruptive for some locals and those travelling on holiday, planning ahead will help everyone get to their destination, says Waikato system manager Cara Lauder.

'Over the past week we have had the road open between 7am and 7pm, and closed overnight. This is to ensure the safety of road users passing through an area that is still seeing active movement. For the safety of our crews and road users we will continue with this for the foreseeable future.

Crews working on SH25a have been abused by motorists.

'This will mean that travellers heading for the eastern side of the Coromandel Peninsula, especially those leaving larger cities such as Auckland and Hamilton, will need to carefully plan their leaving time.”

The site is being monitored daily and boreholes are being drilled to understand the full nature of the movement. New cracks are appearing, including in the eastbound lane available for traffic during the day.

'We have seen the road deform over the past week as the site continues to move.

-Waikato Reporters/Stuff.