Mr Brewer said the council-controlled Auckland Transport had put up an array of small signs around the busy approaches to the bridge to show it was for buses only between 7am and 7pm on weekdays.
But the number of signs had added to the confusion.
"For many who may be heading into the area for the first time in a long time, it is as clear as mud.
"With no time to take it all in, many drivers find themselves on the bridge, nowhere to go, and staring at a $150 fine."
Mr Wood called the signs a "complete dog's breakfast" and said they explained why so many people were still being fined three years after the bridge became a bus corridor.
It emerged in June last year that the bridge linking the city centre and the Auckland City Hospital had netted $2.1 million in 21 months, which prompted Mr Brewer to accuse Auckland Transport of "money-hungry militancy".
The council eventually said it would warn drivers, rather than automatically fining them, and improve the signs.
The $1.25 million in fines taken this year come from cameras which didn't operate for much of January.
"Something's clearly not working and I suspect it's the lack of clear, concise signage," said Mr Penrose.
Auckland Transport chief operating officer Greg Edmonds said in a statement: "In response to assisting the public to better understand bus lane signage on Grafton Bridge, Auckland Transport conducted comprehensive research with its online panel [made up of members of the public] this year.
"Engineering work will commence shortly on the bridge for improved signage and we will update the public when it is ready for implementation."
AA motoring affairs manager Mike Noon said people were becoming confused, rather than wilfully disobeying bus lane signs, and the AA would support a review of the signs.
Mr Noon said the council must take care with bus lane signs, because people who were fined despite not intentionally breaking the law would question whether it was revenue gathering.
Mayor Len Brown welcomed the review. "I remain committed to policing of bus lanes based on education of motorists rather than revenue gathering."
Associate Professor Sam Charlton, of Waikato University's psychology department, said motorists read roads, not signs.
"It's too much and drivers won't pay attention ... I don't know whether confusion is the right word; it's having to think hard, evaluate and decide.
"Usually, we don't want drivers to work real hard to decide whether something is safe or not; we want it to be automatic."
