Waka Kotahi representatives were a no-show at a hui to try and resolve an occupation at its Mt Messenger Bypass site on State Highway 3 in North Taranaki.
But the Transport Agency says the protestors did not respond to an invitation to meet on Wednesday and were told it would not be able to attend the Thursday meeting.
About 20 protesters broke through security fencing five days ago and have set up camp at the summit, erecting tents and a kitchen.
The protesters said they were making a last stand for the Mangapekepeke Valley and the maunga which they believed was being desecrated.
Robyn Martin-Kemp describes herself as a disenfranchised member of Ngāti Tama, which has done a land swap with Waka Kotahi so 20 hectares of its Treaty settlement land can be used for the $280 million project.
The iwi has also received a cash payout of about $7m.
Martin-Kemp said the protesters were speaking up for the Archey's frog, long-tail bats and ancient forest in the project's path.
"We're the voice for those things, for our whenua, for our tiao, our natural world and we feel like this is the last stand before they destroy the last bit of Māoridom, I feel, which is here."
Martin-Kemp was particularly upset that Waka Kotahi was building a cableway at the summit of Mt Messenger.
"Our people weren't actually told about that maunga being cut, we were actually specifically told it was going to be protected, but because they couldn't come up the back way here [the Mangapekepeke Valley], they've had to make a Plan B and they did it only consulting with the trustees and not the wider iwi."
Haumoana White is a kaumātua with Ngā Hapū o Poutama - who have not been recognised as manawhenua at Mt Messenger.
The summit was a special place, he said.
"It's one of the highest points in the community, in the district. Something like 1000 foot above sea-level and it's part of an old trail that went from the coast at Parininihi to the Whanganui River.
"It was a feeding basket and people came here to hunt."
White was angry that Waka Kotahi had cut into the maunga.
"They actually made a statement in the Environment Court that the top of the maunga wouldn't be touched and bugger me days that was the first thing they did. They just took it off and it's just mutilated, the top. It just isn't right."
Poutama Charitable Trust spokesperson Marie Gibbs said the protesters wanted to talk to Waka Kotahi about the option of upgrading the existing road.
"You know it meets all the safety and resilience criteria and all the project goals. It still provides jobs to the local community.
"So, it has all the benefits with about a quarter of the adverse effects, so that's what we want to sit down with NZTA and discuss."
Waka Kotahi representatives agreed to a meeting at a neutral venue when they visited site on Tuesday, Gibbs said.
The protesters booked the nearby Tongaporutu Hall Thursday afternoon, but the transport agency was a no-show.
Waka Kotahi said its representatives visited the site on Tuesday and invited the protestors to meet at a neutral location on Wednesday.
A senior regional manager travelled to Taranaki to attend.
The transport agency said the protestors did not respond to the invite on Tuesday as agreed and instead responded on Wednesday afternoon requesting a meeting on Thursday.
They were told the regional manager needed to return to Wellington and the agency would not be able to attend.
“Waka Kotahi has acted in good faith in responding quickly by attempting to engage with the protestors in a constructive way and provide an opportunity for them to share their concerns," a spokesperson said.
The transport agency has previously said the construction of a cableway on the maunga fitted within the project footprint and was allowed under its consents conditions.
A huge native planting and remediation programme combined with a commitment to pest control in perpetuity would mean the area around Mt Messenger would eventually be in better condition after the bypass was built than it was now, it said.
The protesters, meanwhile, have given no indication they are ready give up their occupation of the site.