(Portland, OR) -- Portland leaders say motorists should prepare now for the shutdown of southbound Interstate Five in about two weeks. The interstate will close for up to five weeks as part of Portland's Rose Quarter Improvement projects. Crews will be working around the clock repairing bridge joints and fixing weak areas of the roadway. The interstate was last repaired to this extent in 1985 -- beyond the 25-year span those repairs were expected to last. During the work, southbound traffic will be rerouted over the Fremont Bridge.