SEATTLE -- Major work on and near the Fremont Bridge will keep buses and trucks off the bridge and will close two of the bridge’s four lanes, Seattle transportation officials said.

Over the next 10 months, crews will demolish and replace the 89-year-old approaches to the bridge.

The bridge will be completely closed for up to 15 weekends during the 10-month period, although the contractor could substitute some nighttime closures for weekend ones.

Of the four bus routes that now cross the bridge, only one will have any service to the heart of Fremont.

Bus routes affected are the No. 26, 28, 74 and 31 routes. The 26, 28 and 74 buses will go over Aurora Avenue North. The 31 bus will travel over the Ballard Bridge.

Part of the Burke-Gilman Trail closed for construction in September 2005. A detour is in place until the trail reopens in spring or summer of 2007.

The work is part of a $42 million project to replace the bridge’s approaches and its mechanical and electrical systems.