(from the map on the city webpage for this project)
From SDOT – they’ve been warning that East Duwamish Waterway Bridge work was about to start, and now we have word that lane closures, between the West Seattle “low bridge” and the downtown waterfront, will start tomorrow – read on for the latest announcement:

The Seattle Department of Transportation’s contractor will begin preliminary work on the East Duwamish Waterway Bridge, setting up lane reductions starting the night of Thursday April 23rd. These partial lane closures are expected to take effect the morning of Friday, April 24th and remain in place throughout the project, until early 2010.

The bridge will remain open to traffic throughout the construction period, with two westbound lanes and one eastbound lane open during peak travel times. During non-peak nighttime hours or weekends, bridge may occasionally be further reduced to one lane in each direction.

The sidewalk on the south side (eastbound direction) of the bridge will be closed for the entire duration of this project and also during the construction of the East Marginal Way Grade Separation funded and
managed by the Port of Seattle.

Eastbound pedestrians and bicyclists are advised to follow the signs along SW Spokane Street as well as Klickitat Avenue SW and utilize the designated crosswalk to cross over to the north side of the bridge where they can share the sidewalk with westbound travelers. Bicyclists, using extreme caution, may also choose to ride in the roadway along with motor vehicles.

The East Duwamish Waterway Bridge connects Downtown Seattle to Harbor Island, and leads to the low-level, South Spokane Street Swing Bridge connecting to West Seattle. For a map and project description, please see http://www.seattle.gov/transportation/bridge_rehab_duwamish.htm