Final Supplemental Environmental Impact Statement (SEIS)

Auxiliary Lanes Design Options

• Recommended: One auxiliary lane in each direction on the new Columbia River bridges and nearby sections of I-5

• Two auxiliary lanes in each direction of I-5 would extend across the new Columbia River bridges in addition to and in combination with existing auxiliary lanes from approximately Interstate Avenue/Victory Boulevard to SR 500/39th Street

The one and two auxiliary lane design options would provide important benefits to highway operations and safety.

Both options received a mix of positive and negative feedback from the public. The one auxiliary lane design option is recommended because it would reduce overall environmental impacts while improving transportation operations and safety. The one auxiliary lane design option is also supported by local transportation agencies.

Bridge Configuration Design Options

• Recommended: Single-level fixed-span bridge configuration
• Double-deck fixed-span bridge configuration
• Single-level movable-span bridge configuration

On Jan. 16, 2026, the U.S. Coast Guard provided a Preliminary Navigation Clearance Determination (PNCD) of greater than or equal to 116 feet based on the revised IBR Navigation Impact Report, the drawbridge logs for the existing bridge, and public comments. The PNCD allows for a fixed-span bridge option.

All bridge configurations would provide important benefits to highway operations and safety and have similar impacts to many resources.

The main differences between the two fixed-span configurations and the movable-span configuration is that the movable span would provide more vertical clearance to accommodate larger vessels and a lower grade for all land-based transportation modes (which would benefit freight and active transportation users in particular), but would periodically disrupt all other land-based transportation modes (personal vehicles, freight, transit, and active transportation) due to bridge openings.

The main differences between the double-deck and single-level fixed-span configurations are that the slightly higher grade of the double deck would impact freight traffic and active transportation users, and the single level would have faster emergency response times (although there would also be more exposure to vehicles) and give users of the shared-use path a greater sense of security due to “eyes on the path.” The fixed-span configurations received generally positive comments from the public, while there was mixed feedback on the movable-span due to the tradeoffs identified above.

C Street Ramps Design Options

• Recommended: With C Street ramps
• Without C Street ramps

Both C Street ramp design options would provide important benefits to highway operations and safety and have similar impacts to many other resources, particularly the natural environment.

While there would be some short-term construction cost savings and reduced visual impacts without C Street ramps, there would be greater impacts to local traffic as traffic that would have used the C Street ramps would be routed to the Mill Plain interchange, thereby increasing traffic volumes on the local street network and requiring additional mitigation.

Both design options received a mix of positive and negative feedback from the public, however there were more comments in support of the With C Street Ramps design option. The With C Street Ramps design option also has more support among local partner agencies.

I-5 Alignment Design Options

• Recommended: Centered I-5 alignment
• I-5 westward shift

Both I-5 mainline alignments would provide important benefits to highway operations and safety and have similar impacts to many other resources, particularly the natural environment.

The I-5 Westward Shift design option would notably increase acquisitions resulting in the displacement of an additional three businesses (with approximately 140 employees) and 33 residential units, and the physical removal of the historic Normandy Apartments. However, the I-5 Westward Shift would reduce the area of acquisition and other impacts to the Vancouver National Historic Reserve Historic District (which includes the Fort Vancouver National Historic Site).

While some public comments noted the reduced impacts to the VNHR Historic District from the westward shift design option, others raised concerns about its effects on safety, congestion, and increased residential and business displacements.

Park and Rides Design Options

• Recommended: Provide parking capacity to accommodate 1,270 vehicles dispersed among up to five park and rides.
• Provide parking capacity to accommodate 1,270 vehicles distributed across just two park and rides: one park and ride with 570 parking spaces near the Waterfront Station and one park and ride with 700 parking spaces near the Evergreen Station. The locations for park and rides that were evaluated included:
  • Potential Waterfront Station park and rides: Columbia Way (below I-5), Columbia Street/SR 14, Columbia Street/Phil Arnold Way
  • Potential Evergreen Station park and rides: Library Square, Columbia Credit Union

All of the park and rides would provide similar benefits to the community by increasing the area from which the transit stations draw passengers and making transit more accessible. There could be minor localized differences in traffic patterns and transit ridership depending on the location of spaces. Dispersing the 1,270 parking spaces across up to five park and rides rather than concentrating the spaces at a single location near the Waterfront Station and Evergreen Station would promote compatibility with local planning goals and plans for multiuse development, multimodal access, and attractive public spaces.

As the Program progresses, the IBR Program team will refine the Program’s transit components, which will contribute to further information on parking needs to support transit ridership. Park and rides would be designed to promote station access, support City of Vancouver objectives to increase downtown mobility, and would include existing parking facilities in downtown Vancouver to help meet the projected demand in areas where City of Vancouver studies show surplus parking supply.