Waka Kotahi NZ Transport Agency says trucks must stop crossing the weight-restricted Kopaki rail overbridge on SH30, south of Te Kuiti, or the bridge will be closed to all traffic.

The ageing timber structure is deteriorating faster than it should because trucks are continuing to use it, despite a maximum weight limit of six tonnes being put in place in late 2021, the transport agency said.

Waka Kotahi Waikato regional manager operations Rob said Waka Kotahi has asked the community and freight industry to spread the word that the bridge could no longer take heavy traffic.

The detour around the bridge is SH4 and Kopaki Road, which adds around 12km to a trip between Te Kuiti and Maniatiti/Benneydale.

Campbell said trucks need to stop using the bridge immediately if it was to stay open for light traffic until the replacement bridge opens in 2023.

“Closing the bridge is a last resort as we know this will be a big inconvenience to the local community,” he said.

“However if trucks continue using this bridge we will be forced to close it permanently and that is the scenario we’re trying to avoid.”

The replacement overbridge, which will be able to accommodate all heavy traffic, is being built alongside the existing one. It began construction in 2021 and is currently scheduled to open to traffic in April 2023.

Due to its age and condition, the existing bridge is being regularly assessed by engineers.