Do we need to improve I-5 transportation capacity across the Columbia River?

Existing Conditions On the Bridge

The two I-5 bridges across the Columbia River are 84 and 43 years old. They are low with lift spans that raise between 30 and 60 times a month The I-5 bridge is a significant bottleneck. The bridge operates as a 2 lane bridge not a 3 lane bridge because: The Hayden Island and SR 14 Interchanges are right at each end of the bridge. Much of the back-up leading to the bridge is caused when vehicles try to enter and exit I-5 at the Hayden Island and SR 14 Interchanges. The outside lane leading to and from the bridge acts like a merge lane for the vehicles entering and exiting the freeway. Unless additional capacity is added at the bridge, no additional vehicle trips will be made in the future through this corridor during the peak period and the peak period will grow.

Should that capacity be used for Transit and/or Vehicles?

Because of their age and design, new transportation capacity cannot be added to the bridges. If additional capacity is needed, it will require:

• A new bridge or tunnel to supplement the existing tunnel or
• A new bridge to replace the existing bridges.

• Estimated cost for seismic retrofit: $120,000,000
• Capital maintenance costs: $38,000,000
• Rehabilitate electrical system: $6,000,000 (funded)
• Replace northbound structure trunnion assemblies: $4,000,000
• Paint southbound structure: $20,000,000
• Overlay the deck: $8,000,000