Traffic is building around the country as holidaymakers travel home after the festive season.
Around midday the NZ Transport Agency reported high traffic numbers on State Highway 1 north and southbound near Auckland.
Numbers were increasing at the Johnstones Hill Tunnel and Puhoi areas heading northbound, and drivers should expect delays.
Southbound traffic was also building on SH1 through Wellsford and Warkworth and the agnecy asked drivers to be patient and allow extra time.
Meanwhile, a crash involving several cars on SH29 on the Tauranga side of the Kaimai Ranges near Tauriko is causing extensive delays.
The crash happened about 12.45pm just past Gargan Rd. Police say the road is blocked.
A police spokeswoman said "three or four" cars were involved but no one was seriously injured.
They are asking motorists to avoid the area if possible.
Drivers in Tauranga were also being advised to avoid the SH2 and SH29A area as the BayDreams Music festival takes place today.
High volumes of traffic were expected from 10am to 4pm and 10pm and midnight.
Turbulent weather is expected to hit later today through to the weekend with thunderstorms, heavy rains and strong gales expected around the country.
MetService is also warning that Auckland could get heavy showers and thunderstorms this afternoon, and to expect surface flooding.
The thunderstorms from Auckland and western Coromandel Peninsula down to Wairarapa, including the ranges of Gisborne and Hawke's Bay, could be severe, MetService warns.
"Driving conditions will also be hazardous with surface flooding and poor visibility in heavy rain.".
Yesterday motorists heading into Auckland on SH1 near Albany faced delays after heavy rain resulted in large areas of surface flooding.