If you thought the Highway 520 Floating Bridge replacement plan was moving forward, think again.

SeattlePI.com reports that Seattle's new mayor is about to swing his support behind a different plan. The mayor likes an option with four regular lanes and two bus lanes.

The 520 Floating Bridge is aging, and fairly small for the 150,000 vehicles a day it carries.

Last November, the state and King County endorsed a plan with six regular lanes -- two more than now.

If the mayor pushes hard for something radically different, it could slow down the process of getting a new bridge built.

KIRO 7 Eyewitness News reporter Rick Price said it's difficult to pin down what's already been spent on bridge replacement planning.

But one person in a recent televised debate put the figure at $30 million.

A McGinn spokesman would not comment on the new plan to Seattle PI.com Thursday night.

McGinn said earlier this week that he doesn't want additional traffic lanes on 520; he prefers high-capacity transit.