More video has emerged of the Auckland Harbour Bridge clip-on lanes swaying as people walk on them.

Footage of a 50-millimetre gap opening and closing during an anti-mandate protest last year alarmed Waka Kotahi.

Documents showed the bridge’s operators had known about the wobble occurring during other mass walks, notably the hikoi led by Dame Whina Cooper in 1975.

Another previous land hikoi in 2004 also set it off, and Mike Millett of the North Shore caught it on camera.

At 1.05 minutes into his short Youtube video, the swaying can be seen.

“You can see the actual gap closing and opening and the crashing of signs on a truck parked up,” Millett said.

Engineers brought in by transport authorities came up with relatively simple options to damp down the swaying in a report in 2010.

Documents showed the bridge's operators had known about the wobble occurring during other mass walks. Photo / Michael Craig

There is no record of what happened next if anything.

“There is no documentation of any decision not to proceed with implementing dampers for pedestrian use of the extension bridges,” Waka Kotahi told RNZ this week.

“The damping is only required if the extension bridge is to be used for walking.”

Emails released under a previous OIA suggested the swaying was a “one of the key considerations” when a Skypath for cyclists and walkers was mooted to be bolted under the clip-ons, but the latest OIA response said: “There were no specific reports in relation to how the box girder vibrations related to the SkyPath.”

The lobby group Bike Auckland sought out the information on the swaying bridge after Waka Kotahi suggested it would be a factor if it ever dedicated a lane for bikers and walkers.

-RNZ