Montlake Lid over SR 520

The old highway bridge across Union Bay went up in the early 1960s on hollow columns, and the engineers later judged those columns a risk in a severe earthquake [1]. The roadway also cut the Montlake neighborhood in two [1]. So the state rebuilt the corridor piece by piece, opening a westbound span in 2017 and then starting the Montlake Project, with construction beginning in summer 2019 [1]. Its centerpiece is a lid: three acres of landscaped cover laid over the highway, carrying regional transit stops and open ground, with direct-access ramps for buses and carpools [1]. Girders went over the freeway in early 2021 to carry that lid [1]. East of it, a separate bridge carries bicycles and pedestrians across SR 520, tying Arboretum trails to Montlake and the University District [1]. The design changed along the way through talks with local governments, designers and neighbors, which pushed the lid toward better connections and more usable open space [1]. The whole job finished in 2025 [1].