People are being warned to prepare for "significant congestion, disruption and delays" when Te Pati Māori carries out protest action tomorrow.
On Tuesday the party will lead protesters in a 'Nationwide Action Day' across the country, likely to take place between 7am and 9am.
Te Pāti Māori said the demonstration is meant to represent "the beginning of a unified Aotearoa response to the Government's assault on Tangata Whenua and Te Tiriti o Waitangi".
The New Zealand Transport Agency/Waka Kotahi (NZTA) and Auckland Transport (AT) warn this could cause "significant disruptions" on key highways and arterial routes in Auckland, Waikato, Tauranga and Wellington.
Smaller centres are also likely to be affected by protest action, which could impact travel on local roads.
In Auckland significant disruptions are also likely on a range of key bus routes such as the NX1 and NX2 Northern Express services and the WX1 Western Express.
Both the NZTA and AT are urging people to plan ahead.
"Road users travelling to work or school are advised to plan their route using the NZ Transport Agency Journey Planner," NZTA said.
"Auckland public transport users should plan ahead before travelling using the AT Journey Planner, or by checking the AT Mobile App for updates. Updates will also be available at AT_TravelAlerts."
NZTA and AT said they will provide real-time travel information and updates to the public via social media during the event.
Assistant Commissioner Sandra Venables says in some areas police will be putting "measures in place to prevent protestors putting themselves and motorists in harm's way".
She said police are working with organisers to provide advice on lawful protest and any health and safety implications. Officers would be "highly visible across the roading network".
"Police recognise the right to peaceful protest and will be reminding protestors about lawful behaviour on our roads," Venables said.
"Unlawful behaviour will result in enforcement action, either at the time or following the event if safety issues prevent immediate action," she said.
Speaking at his post-Cabinet press conference on Monday afternoon, Prime Minister Christopher Luxon said New Zealanders are entitled to protest, but they should act lawfully.
