Fatigue is believed to have caused a crash on the Wellington motorway near Johnsonville that killed a motorcyclist early this morning.

Police said a car was driving south in the northbound lanes of State Highway 1 near Johnsonville when it collided with a motorcyclist at around 3am this morning.

The motorcyclist died at the scene while the driver of the car - a 72-year-old woman - was uninjured.

Police said fatigue is a factor in causing the incident and they are urging people to travel safe over the holiday period.

The woman has been charged with careless driving causing death.

She will be released from custody to appear in the Wellington District Court in the New Year.

The death is the third across the Christmas holiday period.

So far this year, 373 people have died on New Zealand's roads, seven fewer than the road toll for 2017.

Among them is one person who died in Whanganui on Christmas Day, and one in Palmerston North yesterday.

During last year's Christmas and New Year's holidays, 12 people died on the roads.