Documents reveal NZTA officials wanted to put the kibosh on Wellington's kapa haka pedestrian crossing signals.
It's not the first time they've been offside with Wellington City Council's ambitions to make the city more vibrant.
Earlier this year the Herald revealed they were prepared to call in police to stop the city's Rainbow Crossing being painted.
Correspondence released under the Official Information Act shows the special haka lanterns were only allowed after a last minute intervention by NZTA's acting chief executive Mark Ratcliffe.
He said he balanced up the "role as regulator against doing the right thing in 2019".
The signals were installed to celebrate Wellington hosting the country's national kapa haka festival Te Matatini.
Alternative traffic crossing signals are hardly a novelty in the capital.
In fact, there are four different ones at 11 intersections around the city representing Kate Sheppard, Carmen Rupe, Captain Alfred Shout and John Plimmer.
An exemption for these was granted in 2016, but officers said this was against best advice and legal recommendations at the time.
Any alternatives to the green walking human symbol are not legal unless NZTA issues an exemption to rules in the Transport Act.
In a letter declining the council's exemption application NZTA Safety and Environment director Harry Wilson said pedestrian signals must convey a clear and consistent message to road users.
"Uniform traffic control devices make it easy for all users of the transport system including local residents, people from all around New Zealand and overseas tourists to quickly see, recognise, understand and comply with the traffic control devices."
There were significant safety risks in moving away from the uniform signals, he said.
Although conversations about the exemption started in September 2018, the toing and froing between WCC and NZTA continued for months.
A formal letter declining it was penned on February 14 of this year, just a few days before Te Matatini was due to open.
But NZTA's acting chief executive swooped in a day before performers took to the stage to allow the installation to go ahead.
After seeking legal advice, Ratcliffe used his discretion and granted the exemption.
Mayor Justin Lester said the process was extremely frustrating but thanked Ratcliffe for getting the signals across the line.
"We will always try and push the letter of the law but ultimately common sense prevailed, it's 2019 after all and we need to be flexible in how we approach things."
When asked whether the NZTA was comfortable the haka signals were working as necessary, regional relationships director Emma Speight said the agency considered the alternative symbols were unlikely to confuse pedestrians and the risk to safety was not significantly increased.
"The alternative symbols also represent cultural value to Wellington and the Transport Agency is supportive of celebrations of diversity."