So far six cars have been caught by the barriers on Queen Elizabeth II Drive between Burwood and Innes Rds since they were put in.
Between January 2008 and December 2017, there were two deaths and 13 serious injuries as a result of vehicle collisions on the stretch of road.
But in July last year, the barriers - which are designed to "catch vehicles" that leave their lane - were installed along the road as part of a $2.5 million New Zealand Transport Agency road safety project.
Since then, the barriers have been struck six times between Marshland and Burwood Rds.
Vehicles have struck the median barrier twice, potentially preventing head-on collisions, and hit the edge barrier four times, “preventing run-off road or run into tree/ditch crashes,” an NZTA spokeswoman said.
When a vehicle hits a barrier, the wire cables flex, slowing the vehicle down and keeping it upright during and after the collision.
The barrier also absorbs the impact, reducing the force on the people inside the vehicle.
There are no plans to permanently remove the barriers.
“However, on January 20, construction began on a 500m section of the road with barriers to make it wider, after the originally constructed width was found to be slightly short of the planned width," the spokeswoman said
“There is no cost to the transport agency for this remedial work, it is covered in the contract with the contractor."
Prior to the barriers being installed, NZTA worked with Fire and Emergency NZ and other stakeholders to allow for the appropriate width for emergency vehicles to reach crash sites.
