Auckland Council has set up a reference group to work out how to reduce the total kilometres travelled by cars in the city by 20 percent.
It has until December to do so as part of the government's first emissions reduction plan.
Waka Kotahi says almost 17 percent of greenhouse gas emissions come from transport.
AA policy director Martin Glynn told Checkpoint any approach the council took needed to be location specific.
The AA agreed there needed to be a reduction in driving but it had a problem with the government's plan to achieve this.
"We'd like to see less planning and more time figuring out how we can really turn the dial on emissions," Glynn said.
With congestion, the challenge was moving as many people as sustainably as possible, he said.
"We'd like Auckland Transport to apply a more location based approach so what works in the city centre... and maybe around the train stations, isn't going to work in less dense parts of the city.
"They really need to do a bit more thinking about what's really going to work where."
Bus lanes carrying a sufficient number of people "absolutely makes sense" but in outer parts of the city "it can absolutely make things worse", he said.
The plan was longterm, he said, "now's not the time, is it, the whole public transport system's really on its knees".
"We need to be realistic about what we can achieve."
The clean car discount was really successful, and exceeding targets, he said.
The clean car upgrade scheme will be stopped as part of the government's reprioritisation.