"The work will bring the bridge into a state of good repair, improve traffic flow and create needed construction jobs," said Bloomberg at yesterday's ceremony to mark the start of the project.

The project will reconstruct the surfacing over the bridge's masonry arch blocks, install a waterproofing seal and a new drainage system. Steel support structures will be rehabilitated and seismic retrofitting will be carried out. Other activties include expanding an entrance ramp and repainting the bridge's steel.

Contractor Skanska Koch was appointed in January and preparatory work is under way. The project is expected to be completed in 2014.