The alternatives development phase gathered input from technical staff, project committees, participating agencies, and the public to identify alternatives that would address the purpose of and need for the proposed action. Initially, a preliminary range of alternatives was developed that comprised 21 build alternatives located along three project corridors:
- West corridor: Reroute US 97 west of its existing alignment and closer to US 20
- Existing corridor: Retain US 97 on its existing alignment
- East corridor: Reroute US 97 east of its existing alignment and closer to the BNSF Railway
A No Build Alternative was also considered by ODOT and was automatically forwarded into the Draft EIS for evaluation per requirements under the National Environmental Policy Act (NEPA).
This preliminary range build alternatives were assessed in terms of engineering feasibility (operational benefits, geometrical design feasibility), significant environmental impacts, and economic feasibility. From this initial assessment, the range of alternatives was revised based on how the alternatives compared to one another, and the best performing alternative(s) in each corridor were carried forward. The result yielded a combined preliminary range of alternatives, which were then forwarded to alternatives screening to determine which alternatives would satisfy the purpose and need for the proposed action and meet other screening criteria.
Screening criteria were developed to assess whether an alternative would meet the purpose and need for the proposed action as well as demonstrate economic and technical feasibility. The screening process included pass/fail criteria to determine if an alternative would achieve the following:
- Reduce congestion
- Improve traffic flow
- Improve safety
- Be economically feasible
- Improve expressway operations
- Support current and future economic development
- Maintain local street connectivity
Each alternative was sequentially screened through a three step screening process:
Step 1: The first step was a technical feasibility screen and measured whether or not an alternative could carry projected traffic volumes on US 97 while reducing delay, achieving minimum standards and policies set by the Oregon Highway Plan and American Association of State Highway and Transportation Officials, and providing safety improvements.
Step 2: Using system-level traffic modeling analysis, this screening step measured an alternative's ability to reduce congestion and improve traffic operations on US 97.
Step 3: For the final third screening step, critical operational feasibility, environmental impacts, and economic feasibility was assessed across six criteria: total cost, incremental benefits, capacity, expressway operations, economic development, and connectivity.
Of the build alternatives that were screened, only two alternatives, the East DS1 and East DS2 Alternatives, passed all screening criteria and were advanced for detailed study and comparison in this Draft EIS. The No Build Alternative was also forwarded into the Draft EIS for evaluation per requirements under the NEPA. No evaluation of the alternatives' ability to achieve project goals and objectives was performed at this screening phase.
Alternatives Studied in the Draft EIS
ODOT and the project team conducted detailed environmental studies to identify the impacts and benefits of the East DS1, East DS2, and No Build alternatives. The results of these studies are summarized in the Draft EIS. More detail on the alternatives development and screening phase is also included in Chapter 2 of the Draft EIS.
Review the Draft EIS »
Modifications to Alternatives
Since the publication of the Draft EIS and the close of the public comment period in September 2011, ODOT and FHWA have been:
- Exploring opportunities to continue to scale down and modify the alternatives to reduce the impacts, address the DEIS public comments, and reduce the overall cost of the project.
- Looking at whether the north interchange is a necessary design element to meet the congestion, safety and traffic flow needs of US 97 within the 20 year planning horizon.
- Working with local agency partners, reviewing possible modifications to the long-term alternatives and completing traffic analysis to assess operational performance.
ODOT and FHWA anticipate sharing information and getting input on the alternative modifications with stakeholder focus groups, and public in winter 2012/2013. Following that input a preferred alternative will be identified and the Final EIS will be prepared. ODOT and FHWA will also be working with local agency partners to identify incremental phases that can be implemented to improve operations and safety on US 97 while working towards the longer term solution.