Sergeant Alex Pickover confirmed the cause of the crash on Wednesday just before 4.30pm was a driver failing to stop at the intersection of Walkers and Two Chain Rds in Rolleston.
One person was treated for moderate injuries and another for minor injuries.
Said Sergeant Pickover: “I just want to reinforce that stop means stop and the impact at a 100km/h area into another 100km/h area is quite significant and the risk of injury or death is also quite significant.”
Diversions were in place at the scene while emergency services and police responded to the incident.