Mayoral candidates are being asked to do their research before announcing grand solutions to Auckland's congestion crisis.
It comes after long-shot hopeful Craig Lord announced plans to build a monorail around the city.
"There are no rail crossings. The benefit of that goes without saying," he said on Sunday. "Then there is the super advantage of being able to build it pretty much anywhere because it's just poles. This solves the major issue of construction across the unique Auckland geography."
Lord said it would be able to traverse the harbour and other waterways, linking up everything from Wellsford to Pukekohe.
"East, west, north, south, anywhere and everywhere."
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But transport expert and editor of Greater Auckland Matt Lowrie says it's irresponsible to promise such a grand scheme.
"Without understanding where you're going to put them, how much it's going to cost and how you're going to get it all consented, it's really just a pie in the sky," he told Newshub.
"What people really need to understand is there's a lot of work that's been going on to work out what the best options are."
Mayoral rival John Tamihere has promised a double-decker harbour bridge if elected, a plan incumbent Phil Goff labelled "total fantasy stuff and fundamentally dishonest to promise" because it would cost upwards of $10 billion to build.
"Either he intends to bankrupt the city, burden ratepayers with massive extra rates or he is making it up because he knows he is never going to deliver it."
Lowrie says many other cities have learned a monorail is not practical, the hard way - and not just fictional cities like The Simpsons' Springfield.
"Sydney famously had a monorail around the city centre for a number of years, and a few years ago they pulled it out because no one was really using it, and it was costing a lot to operate."
Lord, a former engineer, admits he still has a lot of research to do.