Lanes closed on the Auckland Harbour Bridge and the speed reduced to 30km/h this week. Photo / Michael Craig
Lanes closed on the Auckland Harbour Bridge and the speed reduced to 30km/h this week. Photo / Michael Craig
Waka Kotahi has defended its closing of the Auckland Harbour Bridge during high winds amid criticisms the transport agency was “scare-mongering” with “knee-jerk overreactions”.
The transport agency’s chief executive, Nicole Rosie, responded to the Employers and Manufacturers Association’s (EMA) call for Waka Kotahi to review its policies around closing the bridge.
EMA head of advocacy Alan McDonald rebuked recent closures for causing a loss of economic activity by delaying the trucking of freight and keeping workers stuck on the North Shore.
“Businesses in the central city and workplaces around the greater Auckland region can’t keep putting up with disruptions to their workforces and businesses on the off-chance the bridge might close,” McDonald said.
Waka Kotahi's policies around closing the Auckland Harbour Bridge during high winds have been criticised as 'knee-jerk reactions' that reduce economic productivity. Photo / Michael Craig
In a letter directly to the EMA’s chief executive Brett O’Riley, Rosie said Waka Kotahi had a responsibility to protect public safety and the structural integrity of the bridge.
She said the transport agency’s focus on protecting the bridge recognised its “vital importance to the social and economic wellbeing of New Zealand”.
Rosie told O’Riley the wind speed thresholds were “evidence-based and in line with international best practice”, and had been independently reviewed.
“[The thresholds are] based on recommendations from international operators of structures with similar vulnerability to wind as the Auckland Harbour Bridge,” she said.
Wind speed thresholds prompting speed limit reductions, lane closure and entire bridge closures were lowered after an accident in 2020 closed the bridge for two and a half weeks. Photo / Michael Craig
Wind alert systems and thresholds were independently reviewed by Auercon this year, who found them “appropriate and robust”, Rosie said.
The thresholds were lowered after high gusts of about 127km/h blew a truck against an overarch on the bridge and closed it for two and a half weeks in September 2020.
“Following [that], Waka Kotahi reviewed and revised the high wind intervention thresholds for travel restrictions on the bridge,” Rosie said.
“[That was] in order to protect road users, protect the bridge structure and prevent a recurrence of the serious disruption Aucklanders experienced at the time.
All lanes on the bridge now close when wind speeds reach 90km/h.
“In spite of several extreme weather and severe wind events since the new thresholds were adopted, there have been no further wind-related accidents necessitating closure of the bridge,” she said.
Rosie said it was unsafe for vehicles to use the bridge at speeds that fast. She said the wind direction could also affect how safe it was to travel over it.
“Because the lanes are narrow relative to the vehicles using the bridge, the risk of vehicles being buffeted around by wind gusts is higher, which risks damage to the structure. This is why we close alternate lanes when wind gusts reach a certain threshold.
“If there is potential for sudden and high wind gusts on the bridge, lowering the speed limit gives motorists time to react and take more care.”
Raphael Franks is an Auckland-based reporter who covers breaking news. He joined the Herald as a Te Rito cadet in 2022.
