It's a tale that has become only taller some 75 years after it first emerged - a Kiwi myth born out of commuter frustration and war-time nostalgia.
The story goes something like this:
During WWII, the United States Marine Corps offered to build a four-lane motorway between Auckland and Wellington, while its soldiers were stationed here, but the New Zealand Government turned down the offer, claiming such an extensive motorway would never be needed.
It's true that up to 100,000 military personal from the United States were stationed in New Zealand during 1942-44, as they trained for the invasion of the Japanese-held Pacific.
Up to 45,000 of them were in the country at any one time, and they were housed in 100 specifically built or rented sites in the Auckland, Northland, Wellington and Wairarapa areas.
Could the US Marine Corps help bust the myth?
Newshub contacted the organisation that could perhaps solve the mystery with a bit of basic fact-checking - the US Marine Corps.
Dr Jim Ginther, senior archivist for the Marine Corps History Division, based in Virginia, told Newshub that most of the materials from the corps' time in New Zealand were operationally oriented, but he did check the commandant's personal papers that he had access to.
"I cannot deny that this [the offer] happened, but could not find any evidence of it in our holdings."
But Dr Ginther told Newshub that if an offer had been made to the New Zealand Government to build a motorway, it would have likely come from the US Navy, not the Marine Corps.
"It would seem to me a strange thing for Marines to be involved in, since most heavy construction of this nature would normally have been handled by the Navy," Dr Ginther said.
So, the plot thickens.
Did the alleged offer actually come from the US Navy?
Newshub contacted the US Navy and were told that a major US Naval intelligence base operated in Auckland during the war which housed 300 staff.
Perhaps more importantly, Newshub also learned that the US Navy's Joint Purchasing Board (tasked with acquiring and transporting huge amounts of food and other basic supplies to US bases) was very active in New Zealand from late 1942, until 1944.
A US military official history - The US Army in WW2: The Quartermaster Corps: Operations in the War Against Japan - reveals the importance of the Joint Purchasing Board's work in New Zealand.
"As far as local procurement of Quartermaster supplies and the distribution of food were concerned, New Zealand became the principal rear base.
"From the Quartermaster standpoint, the ration storage centers, established in April 1943 at Auckland and Wellington, constituted the most important installations in New Zealand.
"Operating under the Joint Purchasing Board, they stored both locally procured foods, and those received from Australia and San Francisco.
"They shipped perishable provisions to all South Pacific Bases."
Would the construction of a major North Island motorway been possible?
So it appears, on a logical level at least, that there was a need for the US Navy to build a motorway between Auckland and Wellington to transport crucial supplies more efficiently - but there is no conclusive proof that it made an offer to the New Zealand Government to construct one.
Ministry for Culture & Heritage chief historian Neill Atkinson told Newshub he was sceptical that such an offer would have been made in earnest.
"The US bases, such as those at Paekakariki, were built by the New Zealand Public Works Department, so I don't see how the US military would have had the means to build a major, complex road, without specially bringing in personnel and equipment.
"I suppose infantry could have done manual labour, but they were in New Zealand primarily to train for combat and soon shipped out to the Pacific. And New Zealand would have had to supply all the surveying, bridge construction etc., and most of the machinery," Mr Atkinson said.
"On the other hand, as I live in Raumati, I know some people from Paekakariki and someone told me once he'd heard this story directly from the farmer whose land was taken for the US camps. Whether that's got any basis, I wouldn't know."
When and where would such an offer have occurred?
With some further investigation, Newshub found more possible answers in a book by Kiwi author Michael Bassett.
In his book, The State in New Zealand 1840-1984, Socialism Without Doctrines, Mr Bassett reveals that in 1942, the US Navy's Joint Purchasing Board met several times with New Zealand's National Supply Committee.
It's very likely that the New Zealand Prime Minister at the time, Labour's Peter Fraser, or his Defence Minister, Frederick Jones, attended some of those meetings or were at the very least well aware of the proceedings.
In 1942, it was not known for how long the war would last and while most US troops had left our shores by late 1944, it could have been perceived that they would be stationed here for many more years than they were, even into the 1950s.
Therefore, a plan to build a major motorway between Auckland and Wellington to improve the war effort was not only feasible, but ultimately realistic and was possibly discussed, even in jest, between the US Navy's Joint Purchasing Board and New Zealand's National Supply Committee.
Just because no construction began, or even a detailed plan released, does not mean such an offer can now be dismissed as pure fantasy.
It was only discovered in 2016 that twice as many New Zealanders served at Gallipoli than was previously thought.
Perhaps, one day, concrete proof will emerge that confirms the US Navy once planned to modernise New Zealand's road network to benefit its own ability to wage war.
Myth could eventually become reality.
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