The 103-year-old Ballard Bridge is a major connection across the Lake Washington Ship Canal. The bascule bridge opens for marine traffic, connects the Ballard and Interbay neighborhoods, and is a key link to downtown Seattle. In 1982, it was added to the National Register of Historic Places. While the bridge structure is currently in good condition, it is apparent that it will soon require significant rehabilitation. The Ballard Bridge Study looked at different options not only to improve the structure but also to address functional and operational challenges. The study’s goal was to identify cost-effective solutions embraced by the City and the community, so plans can be made for future improvements and pursuing funding.
Working with teaming partners, SCJ’s design team first analyzed the existing corridor to determine constraints and opportunities. The neighborhood around the bridge is a highly developed corridor that constrains the footprint of a new design, as does the abutting Fishermen’s Terminal. The existing bascule section of the bridge has a fixed, narrow sidewalk, requiring cyclists to get off their bikes and walk across eventually. The only other bike alternative across the Ship Canal is the Fremont Bridge, two miles away. This project also provides a way to address the needs of the bicycle and pedestrian communities. Efforts had to be coordinated closely with Sound Transit to allow for the West Seattle Ballard Link Extension. A parallel bridge structure was not possible, given the tight constraints. One possibility considered was designing a structure high enough to be built over the existing bridge. Another option was to build a temporary structure to the east that uses the same approaches. The team also coordinated with the Port of Seattle and BNSF regarding impacts to their facilities.
Evaluation of these constraints and opportunities allowed the design team to identify possible solutions, begin screening concepts, and package viable alternatives. These include a low-level rehabilitation of the existing bridge, a mid-level replacement that raises the structure approximately 30 feet and reduces the number of bridge openings, and a high-level replacement that eliminates all bridge openings. Each alternative improves bicycle and pedestrian connectivity across the bridge and replaces the Emerson/Nickerson intersection with a single point urban interchange (SPUI) designed by SCJ.
An alternatives analysis followed, comparing impacts on right of way, the environment, traffic operations, cost, constructability, and different modal connectivity. The goal of the analysis was not to select one alternative, but to identify the advantages and disadvantages of each option to help the City make informed decisions as they evaluate the entire corridor. To help clearly communicate the options, SCJ’s Transportation Design team aided in the creation of graphics and boards for public display and represented the City at a series of public drop-in sessions.