Just in from SDOT – read ahead for the full alert:

On Saturday, February 7, the Seattle Department of
Transportation (SDOT) will close the Seneca Street off-ramp of the
Alaskan Way Viaduct northbound from 9 a.m. to 5 p.m. During the
eight-hour closure, a crew will form and pour a 30-foot concrete section
of the off-ramp railing. While the off-ramp is closed, motorists bound
for downtown Seattle will be directed north to the next exit, the
Western Avenue off-ramp.

The final phase of this work, which will be completed the weekend of
March 21, involves replacing a temporary railing that has been in place
since last fall. On October 20, 2008, a truck struck and loosened the
off-ramp railing and, in the process of untangling itself, caused the
30-foot section of railing to fall to the surface street below.