Engineering News-Record » The West Seattle Link Extension, proposed for 2030, includes a new fixed bridge, while the 2035 Ballard Link Extension requires both a new downtown Seattle light rail tunnel and a movable bridge. Both extensions move light rail west of Seattle, with the West Seattle portion heading across the Duwamish River with a 4.7-mile track extension. The Ballard extension runs mostly northwest 7.1 miles and requires a 3.3-mile downtown tunnel.