One person suffered minor injuries but did not require hospitalisation. A ute had ended up on its side, while a station wagon and sedan were also damaged.
Last month the New Zealand Transport Agency announced it would spend an estimated $8.1 million on a new roundabout for the notorious intersection, which was rated as the fourth most dangerous in the country.
In late 2014 the speed limit approaching the intersection was lowered from 80km/h to 70km/h.
Mrs Riordan said police targeted that intersection regularly and still found several drivers who failed to stop at the stop sign.
"For some reason they think it's okay because they are the second or third car in a line of vehicles and they think it's okay to keep going when the one in front goes.
"The message is we make no apologies for the fact we are targeting that intersection because we are in the business of saving lives," Mrs Riordan said.
She urged motorists to exercise more caution and said hopefully the danger level would reduce when the new roundabout went in.
New Zealand Transport Agency communications spokeswoman for Bay of Plenty/Waikato, Natalie Dixon, said no start time had been set for work to begin as the job was still out for tender but it was expected to be some time at the start of this year.
She said installing roundabouts at high-risk intersections was one thing the agency could do to help reduce the number of crashes. Roundabouts naturally slowed traffic and reduced the chance of head-on or side-impact crashes which could be the cause of death or serious injury. Transport Agency data shows that changing a T intersection or a crossroad to a roundabout reduces death and serious injury crashes by 90 per cent. The total number of crashes reduces between 25 to 80 per cent.
Roundabout rules:
* When turning left at the first exit, signal a left turn before entering the roundabout. Continue to indicate left as you exit the roundabout.
* If going straight ahead (taking the second exit) you must signal a left turn as you pass the exit before the one you intend to take.
* If turning right (taking a third or fourth exit) signal a right turn before entering the roundabout and then signal a left turn as you pass the exit before the one you intend to take.