All lanes on Transmission Gully are open after protesters this morning sat across the highway.

Waka Kotahi New Zealand Transport Agency confirmed the road had been cleared shortly after 9.30am.

“The southbound lane was closed for just over an hour from approximately 8am. Drivers heading into Wellington should expect some further delays as traffic congestion on the route eases.”

Protesters from the Restore Passenger Rail movement were sitting on Transmission Gully, blocking the southbound lanes of the road and holding a banner.

Twelve people, aged between 22 and 81, from great-grandparents to students, including a father and son, sat across the motorway.

Protesters on Transmission Gully. Photo / Tayla Capazorio

Rosemary, a spokeswoman for the group, told NZME some protesters have glued their hands to the road.

She apologised to motorists for the inconvenience, acknowledging it was an "extreme" action but said there wasn't much time left to combat climate change.

"Places like Transmission Gully encourage more cars, more emissions - we have got to go the other way."

Rosemary said the group will continue until they get a solid answer from the Government about restoring passenger rail.

"We want a commitment from the Government that they are going to look seriously at producing transport."

Three cars blocked the lane and a police spokesperson said they understood up to 20 people were involved.

"Police are responding, however motorists using the road should expect delays."

Transport Minister Michael Wood blasted the rail protesters who have caused traffic chaos across Wellington in recent weeks, calling their actions "dangerous, stupid and counter-productive".

Wood told NZME the Government is working with plenty of railway advocates who he says push the Government to "do more and do it faster".

"We sit down with them, and we're making progress – this stuff does exactly the opposite.

"These people and others who have recently granted themselves the right to disrupt people in large numbers – people like Brian Tamaki marching across the Harbour Bridge – need to reflect a little bit on how their actions affect others."

Waka Kotahi New Zealand Transport Agency warned that State Highway 1 was closed to southbound traffic, and motorists should detour via State Highway 59.

The group has blocked roads four times in the past fortnight.

Yesterday, two people abseiled down over the Mt Victoria Tunnel and hung another banner, forcing the closure of the tunnel in both directions.

Te Wehi Ratana, a spokesman for the Restore Passenger Rail group, called for the Government to immediately restore passenger rail throughout the country.

"I'm up here sounding the alarm for urgent climate action," he said. "We're in a climate emergency."

The two protesters were arrested and charged - joining others who were charged with criminal nuisance and wilful trespass last week for sitting across the motorway at the Terrace Tunnel, and again at the Melling Intersection of State Highway 2.