Whether the additional lane will get the go-ahead is to be decided at Friday's greater Christchurch urban development strategy implementation committee meeting.
"Our biggest concerns are, has this third lane proposal considered where all the extra traffic will go after the bridge? It's already bottle-necked after the bridge and at Belfast and into Northcote, Casebrook, Papanui and St Albans," community board chairwoman Ali Jones said.
But she thinks there is a need to change the way people travel into the city from North Canterbury without encouraging more cars.
"We all want to improve the amenity for our residents, while being as environmentally minded and fiscally responsible as we can," she said.
Jones said there has been no consideration for the proposed rail system from North Canterbury through to the city that is now being campaigned for and which would cost less than $2 million.