Police in Canterbury are warning drivers to take extra care as icy rural roads cause problems for motorists.
Sergeant Dan Harker says Selwyn police were called to six crashes in six hours on Tuesday. Police were called to seven crashes on Monday.
Drivers are warned to slow down, particularly in shaded rural areas where thin black ice may not be visible.
Mr Harker attended one crash on Monday, during which time he witnessed four more and says conditions are the worst he has seen in many years.