CARS would be removed from at least one lane on Melbourne's Princes Bridge under a plan to make the city more bike-friendly.

Melbourne City Council is considering giving cyclists a dedicated lane on the bridge, which would cost about $150,000 and be in place as early as May.

The RACV has blasted the idea, saying it would increase commuter congestion and pose safety problems on the bridge and at the "complex" T-intersection of Swanston and Flinders streets.

The council's Bicycle Plan 2012-16 proposes installing "chevron-separated lanes by removing one lane of traffic".

"This will increase the capacity of a major link to the central city, improve safety and reduce pedestrian/cyclist conflict," the plan says.

VicRoads and City of Melbourne are using traffic modelling as part of planning.

Cr Cathy Oke, who chairs the City of Melbourne's transport committee, declined to comment before the design was signed off.

RACV general manager of public policy Brian Negus said removing at least one lane of traffic appeared to be a cheap option.

"They should either be looking at changing the cross-section on the footpath or indeed looking at another separate bridge for bicycles," Mr Negus said. "Our interpretation of what is briefly outlined in the document is one lane of traffic disappears in both directions.

"It is just an unacceptable proposal in what is already a busy area. This will make it significantly worse from a congestion point of view and it becomes a safety issue as well."

Mr Negus called on the council to undertake a feasibility study for a new pedestrian and cyclist bridge next to Princes Bridge.

Council spokeswoman Irene Vlahos said the proposed works on Princes Bridge were part of $5.6 million allocated in the 2012-13 budget to improve the city's cycling network.

"Vital to any works is improved safety and consistency for all road users," Ms Vlahos said. "Planning for this project is under way and we are working closely with VicRoads on the concept design."

Twenty-two cyclists were injured after smashes on Princes Bridge between 2008 and 2010, according to VicRoads statistics. Bicycle Network Victoria counted 1864 bikes on the bridge between 7am and 9am during its annual counting day earlier this month.

Mr Negus said the RACV also opposed council building a $2.4 million separated bike route on La Trobe St.

amelia.harris@news.com.au