Waka Kotahi NZTA is finding the time and money to plan a celebratory bike-ride over Auckland Harbour Bridge
The $700,000 event - scheduled for November - is in place of an actual trial of cycling and walking use, which was asked for by the Transport Minister.
The two east clip-on lanes will be opened to walkers and cyclists one Sunday morning for several hours.
Minister Michael Wood asked Waka Kotahi last year for a trial "over the quiet summer months or a long weekend if it can be done safely", OIA documents reveal.
The agency responded with its celebratory event plan and stressed in internal documents that "this is not a trial that would set an expectation that further consideration will be given to providing live lane access".
Wood's request followed the rapid collapse of the government's near-$800m separate cycle-bridge over the Waitemata idea. It was canned within three months of its announcement last year - though Waka Kotahi had spent tens of millions of dollars planning the bridge.
Cycling lobbyists have also been pushing for such a trial and have taken to the bridge in defiance on occasion.
Waka Kotahi is under intense pressure amid a raft of road-building projects that face supply chain and cost woes, including the tortuous negotiations to get the billion-dollar Transmission Gully motorway near Wellington open after two years of delays.
Waka Kotahi initially responded to Wood's trial request saying the bridge "was not designed for a walking and cycling function and there are a range of complex issues that need to be balanced if a trial was to go ahead".
This was followed in December by the board instead endorsing a series of cycling and walking events, starting with a $700,000 one on a Sunday morning some time in November. It would take many months to plan for, event managers told NZTA, requiring temporary steel barriers, an evacuation plan in case high winds hit, and a plan for ambulance access.
Among the options was a "private" event in which people would pay to cross.
The agency rejected that, and said in a paper from its investment and delivery committee: "A single or series of public events open to all would provide the opportunity for Waka Kotahi to partner with Auckland's civic leaders to enable a flagship series of events to align to the Emission Reduction Plan.
"A regular series of events would provide Aucklanders with an opportunity to celebrate the city's natural attractions, bringing some relief following the challenges of 2020."
The bridge events do not move the agency any closer to figuring out a medium or long-term way of allowing cyclists and walkers to get across the harbour on their own steam.
"Undertaking a trial as the minister has requested could set unrealistic expectations around the likelihood of a dedicated lane becoming available in the short term," Waka Kotahi said.
"Any trial would be better targeted at how an overall mode shift to reduce demand over the bridge could be achieved.
"We have not done the work to suggest what those levers for change are and how they could be tested."
But the "levers" to try to cut traffic would be looked at as part of current investigations into medium-term solutions, which include using ferries and buses to move bikers, it said.
Modelling shows taking one vehicle lane out to turn into a walking and cycling lane would require a reduction in bridge traffic of 17,000 vehicles a day just to have a neutral impact on Auckland traffic, it added.
Medium-term "options that structurally connect to the existing AHB will not be considered", it said.
Several years ago millions were spent on engineering designs to hang a cycle-walking path beside or under the bridge, which was seen as the lead contender.
The agency expects to pay for the bridge events, which it initially costed at $400,00-$500,000 each, and will seek sponsors.