Noticed a sign for this while on an off-peninsula errand earlier today: Northbound I-5 will be closed at S. Dearborn (just north of I-90), 9 pm Monday night until 4:30 am Tuesday, for, the Construction Lookahead says, “installation of a new overhead sign structure.” As a result: “Traffic will be detoured to the northbound collector-distributor. The Northbound I-5 off-ramp to Edgar Martinez Dr. S. will also be closed.”