Is a tunnel actually viable for crossing the Columbia River?

Quantity errors in the Interstate Bridge Replacement (IBR) project, which previously led to cost increases, have resurfaced, raising questions about the feasibility of an Immersed Tube Tunnel (ITT) option for the crossing of the Columbia River. https://tinyurl.com/3xc47w25 #InterstateBridgeReplacement #IBR #ImmersedTubeTunnel #ITT #ColumbiaRiverCrossing #CRC #GregJohnson #IBRProgramAdministrator #TunnelConceptAssessment #ExcavationCalculations #MarineTrafficClearance #HaydenIsland #RepurposingCurrentInterstateBridgeStructures #SeismicRiskReduction #ODOT #WSDOT #MAX #LightRail #TrafficCongestion #RiverTraffic #VancouverWa #ClarkCountyWa #ClarkCountyNews #ClarkCountyToday