Bay of Plenty motorists have been warned not to travel if they do not need to due to concerns over bad weather and driver inattention.
Waikato police have asked drivers to keep off the roads if possible, to alleviate the region's gridlocked roading network.
District road policing manager Inspector Freda Grace said between 6am and 2pm today, emergency services have been kept busy attending and trying to clear several crashes.
Mrs Grace said a number of the crashes have involved commercial vehicles including one which closed the intersection of SH2 and SH25 at Mangatarata about 9am when a truck hit a barrier.
Read more: Severe thunderstorm watch for Bay