From: “Kevin Peterson” <petersondesign@centurytel.net>
Subject: Columbia River navigation and the I-5 Bridge
Date:  November 24, 2025 at 10:14:19 AM PST
To: <D13-SMB-D13-LNM@USCG.MIL>

November 24, 2025

Kevin Peterson
Transportation Architect 165 White Point Road Friday Harbor, WA 98250
petersondesign@centurytel.net
(206) 369-8048

Commander B.J. Harris
U.S. Coast Guard Northwest Jackson Federal Building 915 2nd Ave
Seattle, WA 98174
D13-SMB-D13-LNM@USCG.MIL
 
Subject: Two Navigation Related Alternatives for the I-5 Interstate Bridge at the Columbia River Coast Guard Evaluation Effort

Dear Commander Harris,

On behalf of a volunteer group of transportation professionals, I write to share that other I-5 bridge options exist with comparatively significant river navigation benefit. We will soon be finalizing a document sharing these alternatives. Before finalizing the work, we wish to assure ourselves that our work provides the Coast Guard with adequate documentation allowing informed evaluation.

We believe any I-5 bridge should enhance, rather than diminish, safe passage for mariners, preserve future opportunities for shippers, enhance communities near I-5 and the navigation channel, and enhance commerce benefiting from this critical waterway.

This study will introduce two conceptual alternatives that preserve existing navigation clearance or meet upriver navigational clearances while delivering superior urban mobility, safety, and cost efficiency. We are presently nearing completion of a DRAFT ‘White Paper’ sharing these alternatives.

This letter informs the Coast Guard of our efforts, seeks Coast Guard guidance on how best to submit the ‘White Paper’, and requests input with respect to including information or data adequate for an informed evaluation.

The Two Alternatives

1. Immersed Tunnel
   • Places the I-5 mainline beneath the navigation A 27 ft navigation depth using a river datum of +5.28’ for the navigation channel is assumed.
   • Road grades ≤ 4% for safe and efficient traffic
   • Re-purpose existing I-5 bridges to function as a local collector-distributor (C-D). Nearly 50% of project area trips are local, suggesting a good match for a C-D. This eliminates weave conflicts and greatly reduces congestion caused by delays and accidents on the interstate. This results in the navigation channel having clearances that presently exist; 178’ vertical.
   • Straight roadway alignment just upstream of the existing
   • This alternative requires 8–10 FEWER developable urban blocks compared to the IBRP
     
     
2. High-Level Fixed Bridge
   • Provides 144 ft vertical clearance, matching the upstream I-205 navigation vertical clearance. This will reduce the navigation channel clearance between I-5 and I-205 from 178’ to 144’. This vertical clearance is set by Part 77 airspace use.
   • Road grades ≤ 4%.
   • Assumes protective dolphins to canalize river traffic and shield downstream structures, and a main span of approximately 800’.
   • Conservative concrete segmental box girder bridge Four in-water piers aligned with piers of the existing bridges will be suggested.
   • As with the immersed tunnel alternative, existing bridges are retained for C-D roadway
   • Requires restoring Pearson Airfield’s original displaced threshold without reducing runway length. This requires taking one property just east of the runway.
   • Requires 7 – 9 FEWER developable urban blocks compared to the IBRP

Both alternatives conform with AASHTO and state urban freeway standards. Of interest, most Department of Transportation state design manuals require a collector-distributor roadway to be considered when urban interchanges are spaced closer than one mile, in the I-5 bridge area five interchanges exist in less than three miles.

‘White Paper’ Contents

Contents of the ‘White Paper’ presently include:

• Plan & profile drawings for both
• Urban integration studies sharing urban integration
• Narrative and graphic summary of assumptions, comparative benefits with respect to navigation, land use, mobility (general traffic and transit), costs, and regulatory compliance.

Our Respectful Request

We understand the extraordinary demands on Coast Guard resources and the rigorous standards required for bridge permitting. As unpaid citizens, we have invested many hundreds of hours in considering and identifying viable alternatives. We hope our work is detailed enough to demonstrate feasibility, but not so prescriptive as to prejudge future discoveries when a formal Type, Size, and Location (TS&L) study is undertaken.

Schedule

Our intent is to share with the Coast Guard a DRAFT ‘White Paper’ soon after Thanksgiving.

After submitting the DRAFT ‘White Paper’ to the Coast Guard we respectfully ask for a brief cursory review to confirm:

1. Whether materials being prepared enable a meaningful comparative evaluation of navigation
2. Any critical missing information that might impede or prevent informed
3. Feedback regarding specific criteria like navigation clearances, river datum, that may not be correct

This input allows us to modify the final ‘White Paper’ satisfying technical needs for an informed evaluation.

To this end, we request a brief telephone discussion soon after the Coast Guard has conducted a cursory

review of the DRAFT ‘White Paper’. The intent of the phone call is to identify materials that may not be adequately presented potentially impeding CG evaluation. This may be a ten-to-twenty-minute conference call, to take place at your convenience.

Formal submission of the ‘White Paper’ before the end of the year.

Our Respectful Request

We understand the extraordinary demands on Coast Guard resources and the rigorous standards required for bridge permitting. As unpaid citizens, we have invested many hundreds of hours considering and identifying viable alternatives. We hope our work is detailed enough to demonstrate feasibility, but not so prescriptive as to prejudge future discoveries when a formal Type, Size, and Location (TS&L) study is undertaken.

Our Goal

If a new bridge is built over the Columbia River our goal is for the best possible outcome, an outcome beneficial to navigation, effective land, sea, and air mobility, enhanced urban vitality, and the best possible use of public money.

We are saddened that the IBR project office has not considered, properly evaluated, or simply refused to consider significant professional or public input, especially when project sponsors have spent tens of millions of taxpayer dollars soliciting input. We are satisfied that clearly better alternatives exist and look forward to making this project beneficial, efficient, and successful.

Thank you for considering this citizen contribution. With utmost respect and gratitude,

Kevin Peterson