The Marquam Bridge /ˈmɑːrkəm/ is a double-deck, steel-truss cantilever bridge that carries Interstate 5 traffic across the Willamette River south of downtown Portland, Oregon. It is the busiest bridge in Oregon, carrying 140,500 vehicles a day as of 2016. The upper deck carries northbound traffic; the lower deck carries southbound traffic. Proposals have been made to replace the Eastbank Freeway portion of I-5 with a tunnel, connecting with the existing alignment at the Marquam Bridge and the Rose Quarter. This would free up space along the Willamette River for development.