To achieve the best possible solution for the future of I-84 we need to consider many alternatives. Because of the complexity of the project and its setting, the development and evaluation of alternatives will take place over several years. Considerable engineering, traffic analysis, and environmental analysis are necessary to understand the benefits and impacts of each alternative. Getting to the best solution will also require the input of many stakeholders.
There are four mainline alternatives, which are designated by their vertical elevation relative to the ground. These include:
- Alternative 1, The No Build Alternative, must always be considered as a baseline condition. However, in this case, the No-Build means keeping the existing I-84 configuration. Although called a No Build because it does not change I-84’s configuration, this alternative actually involves a lot of construction, as it includes replacing many bridges on the existing alignment, as needed.
- Alternative 2, the New Elevated Alternative, replaces existing I-84 with a new highway which is also elevated above ground level. Under this alternative some different scenarios are possible for certain interchanges and local roadway networks..
- Alternative 3, the Lowered Highway Alternative, replaces the existing I-84 in the study area with a new highway at a lower elevation—either at ground level or below ground level in a cut section. As with Alternative 2, this option allows various different interchange and local roadway scenarios.
- Alternative 4, the Tunnel Alternative, replaces the existing I-84 by putting much of the highway in the study area into a tunnel section. Because much of I-84 would be below ground level, interchange options are limited to the ends of the tunnel section.
Interchange and Local Road Options
A key factor in evaluating the alternatives is how and where each alternative connects with local roadways. Each of the three build alternatives has many interchange options. To see more about the many options and/or give us your feedback on those options (or your ideas for new ones), please visit our interactive alternatives page.