Just one month after Transmission Gully opened to traffic, nearby residents are complaining of "disruptive" and "ridiculous" road noise from a major bridge.

The $1.25 billion road north of Wellington opened to traffic at the end of March after years of budget blowouts and delays.

The opening of the four-lane motorway has largely gone smoothly, but residents living in Takapu Valley have been left less than impressed.

Nature photographer Rob Suisted lives in the valley and said they expected a little bit more road noise when the motorway opened, but they didn't expect "loud clunking" from the joints on Te Ara Toa (bridge 20).

Te Ara Toa is the largest structure on Transmission Gully standing 60 metres above Cannons Creek and stretching 230 metres in length.

Suisted said the noise the new bridge makes is incredibly disruptive.

"Road noise becomes like white noise, you kind of get used to it, but the problem with the clunking of the road joints is you just never do. It's just a random clunking and it echoes."

He said the Takapu Valley community is frustrated by the noise because they have a lot of natural quiet there.

"Also, this is in Belmont Regional Park so anyone using the park is going to be subjected to noise and it's unnecessary.

"I mean they've won awards for this bridge, it's New Zealand's second biggest viaduct so it's had a massive amount of engineering expertise put into it and they can't even make it quiet, it just seems ridiculous."

Suisted said they had been in touch with a Transmission Gully stakeholder manager but that hadn't proven particularly helpful.

"It just sounds like a fob off to us, he basically said if the joints are installed properly than tough luck."

Ventia is the company tasked with maintaining and operating the road and says the noise coming from the bridge is within acceptable levels.

"While we sympathise with the residents who are finding this change in their environment challenging, the noise levels recorded to date are not excessive as per the NZ noise standard for residential areas near new motorways."

A spokesperson told the Herald Te Ara Toa (bridge 20) in particular has joints at each end to allow for expansion of the steel structure.

"This can result in a sound as vehicles pass over the joint. The project believes the consented noise mitigations have fully satisfied the requirements of the NZ standard and while the builder will monitor noise levels at the time prescribed by the consent, we are not considering more mitigations at this time."

Ohariu MP Greg O'Connor told the Herald he was aware of the noise issues and was going out to visit Takapu Valley in the coming days to experience it for himself.

"We'll work out what, if any strategy can be put in place to mitigate it [the noise] once we work out what the problem is and the extent of the problem."

However, O'Connor said it's unlikely any major immediate steps would be taken.
"I don't think anyone will be advocating for the shutting down of Transmission Gully [with] Wellingtonians having waited so many years for it to happen.

"But that doesn't mean where there are local issues that there's not a way of mitigating the impact on local communities."