The Joint Transportation Committee heard on‑the‑record presentations on a Washington State Department of Transportation study that models how the state’s transportation system would need to adapt if barge traffic on the Lower Snake River could no longer move freight.

"This is not about whether the Lower Snake River Dam should be removed or not," JTC project manager Dave Catterson told the committee, framing the study as an effort to assess how the state might prepare for that contingency. WSDOT project lead Jim Mayhew described a four‑phase study that inventories current freight flows, tests scenarios for 2020 and 2045 with and without dams, and will produce a final report due at the end of 2026.

The study uses a "total logistics cost" model to estimate how freight — particularly wheat, which accounts for roughly 70% of barge tonnage cited by presenters — would shift among barges, unit‑train rail terminals, short‑line rail and trucks. Presenters described scenario 5 (new unit‑train terminals at Lewiston and Central Ferry), scenario 6 (expanded short‑line rail feeding Tri‑Cities for transloading), and a combined scenario 7 that tests many interventions for cost‑effectiveness. A scenario 8 will be defined after results are evaluated.

WSU’s independent review team, led by research professor Eric Jessup, said the wheat model has improved but retains limits: coarse spatial resolution in some townships, some inaccurate facility locations, and routing choices that previously routed trucks onto non‑traversable gravel shortcuts. Jessup said those issues have been narrowed but recommended additional "shock" testing — strong, hypothetical disruptions — and more granular validation before relying on final outputs.

Committee members pressed staff on the study’s geographic and economic scope. Mayhew said the model covers flows originating in central Idaho and northeastern Oregon into Washington nodes, but it does not model policy or transport changes inside other states. On economic effects for farmers, WSDOT said the transportation model will report changes in per‑ton transport costs and tonnage shifts but will not predict downstream farm exit decisions; WSU said its outputs could be fed into economic models to assess farm viability.

Presenters said the model includes transloading costs and will produce cost estimates for each scenario and specific improvements. They acknowledged some delays in model development that paused advisory committee meetings for about four months and said community engagement will continue as results are refined.

The committee did not vote on any action. Staff said cost estimating, continued validation and outreach, and a final WSDOT report are the next steps.