A Ridgefield, Wash., contractor begins work Monday morning on a $4.2 million project to replace open steel grating on the Morrison Bridge's lift span.
The project will require some traffic interruptions and detours until it is completed late in the year.
Multnomah County officials said the work would improve safety by replacing the steel grating with a solid surface that provides greater traction for motor vehicles. The contractor, Conway Construction, begins work on the south side of the lift span and will shift to the north side.
The open steel deck grating was incorporated into the Morrison Bridge's design when it opened in 1958 because it was light and still could hold heavy vehicle traffic. The old steel grating will be replaced with fiber reinforced polymer panels. A similar system was installed on the Broadway Bridge in 2005.
Impacts to bridge traffic include:
• One eastbound traffic lane will remain open from Southwest Second Avenue to Interstate 5 northbound/Interstate 84 eastbound, and to Southeast Belmont Street and Martin Luther King Jr. Blvd./Highway 99E throughout the project.
• Access from I-5 S/I-84 westbound to the Morrison Bridge and downtown Portland will remain open throughout the project. The Southwest Naito Parkway ramp to the Morrison Bridge will be closed during the project.
• Westbound access to the bridge from Southeast Morrison Street and Martin Luther King Jr. Blvd./Highway 99E will be closed until late 2011.
• Work on the south side of the lift span will require the path on the south side of the bridge to be closed. The bridge's north sidewalk will remain open when the south path is closed.
• The ramp from the bridge to Southeast Water Avenue will also be closed during work on the south side of the lift span.
Due to the work, only one drawbridge leaf will be able to open for river traffic during most of the project.