The development of potential alternatives has been ongoing since 2014. Early on, the Project Team considered four highway alternatives. These include:
Alternative 1, No-Build Alternative would keep the existing I-84 configuration. This alternative still involves a lot of construction, because many bridges would still need to be replaced. As required by law, the Project Team is still carefully considering the No-Build Alternative.
Alternative 2, Elevated Highway Alternative would replace existing I-84 with a new highway, which is also elevated above ground level. The Project Team has recommended the elimination of the Elevated Highway Alternative because it does not satisfy two of the project’s three primary needs: Traffic Operational and Safety Deficiencies, and Mobility Deficiencies.
Alternative 3, Lowered Highway Alternative would replace the existing I-84 with a new highway at a lower elevation—either at ground level or below ground level in a cut section. The project team is also continuing to refine the highway and ramp options for the Lowered Highway Alternative. To view what the corridor can look like, take the 3D interactive tour.
Alternative 4, Tunnel Alternative would replace the existing I-84 by putting much of the highway in the study area into a tunnel section. After careful consideration, analysis, and feedback from the Public Advisory Committee and public, the Project Team has recommended the elimination of the Tunnel Alternative because it is not economically feasible. Other issues include the following:
• All of the Tunneled Highway Alternative options would have significant property impacts, more than the Elevated Highway Alternative and the Lowered Highway Alternative.
• The construction duration of the Tunneled Highway Alternative would likely be longer than any other alternative.
• There could be prohibitions to some truck traffic, such as trucks carrying fuel and other hazardous materials.
• Three of the four Tunneled Highway Alternative options would require a relocation of a portion of the Park River Conduit, presenting additional construction, design, and permitting challenges that would further escalate the project's schedule and cost.