Hamilton Police spokesman Andrew McAlley said the crash, which happened on an 80km/h stretch of the four-lane highway, would not be referred to the IPCA because it was not a police pursuit and no-one was injured.
However he said police would still investigate it. Mr McAlley would not say if the officer was a man or woman.
Traffic was reduced to two west bound lanes for a short period of time before returning to normal about 2.35pm.
Cobham Dr feeds traffic through a bypass of the city from State Highway 1 in the south and north, as well as into Hamilton itself.
A motorcyclist was killed near Te Kauwhata in April last year when a veteran highway patrol officer performed a u-turn on the brow of hill to chase a speeding driver.
Senior Constable Michael Lenihan was cleared of dangerous driving causing death but convicted of a lesser charge of careless driving for making the u-turn which led to the death of 37-year-old Paul Brown.
Mr Brown crashed into Lenihan's police car at high speed on Waerenga Rd as the officer tried to pursue another motorist.