A study by the King County Department of Transportation, which the city council discussed Monday morning, concludes that a cable-stayed or steel trussed pedestrian bridge over I-5 between North Seattle Community College and the planned Northgate light-rail station would cost between $16.2 and $18.5 million, less than the original estimate of $20 million.
and that two of three potential locations studied are feasible in that price range. Those two potential alignments are identified as alignments 2 and 3 in the image below; alignment 2 would be slightly less expensive. (Alignment 1 was deemed to be too steep). Either alignment would be between about 1,000 and a little over 1,100 feet long.
The bridge would be between 12 and 14 feet wide, would not require Sound Transit to buy any private right-of-way and would take two-and-a-half to three years to build. (The land for the bridge would be donated by the college and the state.)
Northgate pedestrian bridge proponents, including city council member Richard Conlin, have questioned Sound Transit's plans at Northgate, which include a large new parking garage for commuters; after several public meetings at which neighborhood residents expressed their desire for more bike and pedestrian access to the station, Sound Transit agreed to commit $5 million to the bridge or other bike and pedestrian improvements at the station instead of parking.
According to the county's report, building the bridge will "directly support regionally adopted growth management plans that emphasize high-density, transit-supported mixed-use growth centers, reduce average walking time to the station by 30 percent, and expand the station's "walkshed" (the area in which the station is accessible by walking) to more than 150 new buildings and expand the "bikeshed" to more than 3,000 new buildings.
Conlin was out of town and unavailable for comment.