The EMA welcomed a new report outlining the economic benefits of a four-lane expressway into Northland, saying it is further evidence that the government needs to get on and build it.

The report by NZIER found a new high-quality expressway between Auckland and Northland would boost national GDP by $2.1 billion by 2048 and deliver more than $560 million in direct economic benefits to Northland every year.

EMA Head of Advocacy Alan McDonald says the current road between Auckland and Whangārei is a national disgrace, and the report highlights the urgent need to build a resilient, high-quality expressway connecting the two regions.

"It is unacceptable that State Highway One over the Brynderwyns continues to be closed for long periods of time, effectively cutting Northland off from the rest of the country," says McDonald.

"Northland should be one of the wealthiest regions in New Zealand, given its climate, natural resources, and proximity to Auckland. But it is being held back by the poor quality of the main connecting road."

McDonald says business relies on moving goods and services to market quickly, and the reality is that it is easier to move goods from the Bay of Plenty and Waikato to Auckland than it is moving them from Northland to Auckland.

"As a result, we have seen the Waikato and Bay of Plenty regions boom in recent years, especially following the completion of the Waikato Expressway, while Northland has been left to languish behind," says McDonald.