A learner driver with three passengers in his car went airborne as he lost control on State Highway 2 between Norman Ave and East Taratahi Rd in Carterton on Thursday evening.
Police on the scene said the southbound Nissan Primera, with an adult passenger and two children under 5, overtook one vehicle then undertook another, before wobbling out of control and rolling, narrowly missing a northbound cattle truck as it flipped over the safety barrier about 5.30pm.
All escaped without injury, with the children restrained in car seats.
The crash caused traffic diversions down Cornwall Rd and Hughes Line from Masterton. Police said there were about 75-metres of skid marks leading to the vehicle.
They said it was questionable as to the status of the vehicle's warrant of fitness, with one police officer noting that one of the car's tyres was balding.
The driver was on a learner's licence, but no alcohol was involved, said police.