"Where possible, check the weather and road conditions before you leave so you can change your plans and route if necessary.
"We will have additional staff out in the district to manage the roads and ensure people are being safe and driving to the conditions," Mr Grantham said.
Police also remind motorists to wear a seat belt, slow down where necessary and be aware of other road users who may not be easily seen - like cyclists, motorcyclists and pedestrians.
"If you are in a slower vehicle, please pull over when it is safe to do so and let faster vehicles past; traffic build-ups can cause inattention and accidents," Mr Grantham said.
The warning from police comes just days after a horror crash killed three young people on the Desert Rd on Tuesday morning.
Arshpreet Kaur Sidhu, 23, Monalisa Alofaifo, 20, and Twinkle Ansal, 20, died when the car they were travelling in lost control as it approached a 65km/h bend on State Highway 1 at Rangipo, on the Central Plateau, and spun before colliding into a southbound truck.
At the time, Taupo road policing Senior Sergeant Fane Troy said the Desert Rd was notorious for changing conditions.
"You can have beautiful weather on one side of the hill and on the other side you can have black ice and ice and snow, so we encourage all motorists to take extreme caution when travelling through the Desert Rd area and in fact on all roads in New Zealand and just drive to the conditions."
The forecast:
Weather Watch analyst Philip Duncan says it's going to be wet in the west this weekend, with heavy rain in and strong wind in many parts of the country:
Today:
A mainly risk-free day, but overnight rain for the West Coast of the South Island will become heavy, while western parts of the upper North Island will see rain too - although not as bad as the South Island's West Coast, Duncan says. Northwesterly winds will strengthen overnight about the Cook Strait and inland parts of Canterbury and Marlborough.
Tomorrow:
Heavy rain is forecast for the West Coast of the South Island, Duncan says. The North Island will see heavy rain move onto the southwestern corner in the evening, then gradually moving northwards overnight. Strong northwest winds for the upper South Island are forecast in the east in the morning, but will ease in the afternoon. The Cook Strait and much of the North Island (especially in the west) will see strong northwesterly winds, Duncan says. Cook Strait and exposed western areas will likely see gales at times from afternoon and the East Coast may see gales in the evening.
Sunday:
A strong westerly airflow lies over the whole country on Sunday. Duncan says western regions will naturally feel this the most, as will some eastern regions - especially Southland and Otago.
