Concept Analysis Process

Summary

Several river crossing improvement concepts were developed with input by the public. In order to simplify the process of selecting a preferred concept, a decision matrix was utilized to provide a means to identify and evaluate the advantages and disadvantages of each concept. The matrix provided a tool to compare and rank each concept in relation to each other. These rankings allowed the identification of a preferred concept(s), taking into consideration the technical and social concerns of the community. In summary, the decision matrix analysis involved a four-step process that includes:

1. Develop a list of evaluation criteria.
2. Determine "relative importance weighing" for each evaluation criteria.
3. Score each evaluation criteria for each concept.
4. Calculate the weighted scores for each concept.

Evaluation Criteria

The project concepts were individually evaluated using the following nine criteria, each of which was important in the overall determination of the best river crossing solution:

• Historic Preservation
• Public Safety
• Environmental Sensitivity
• Right of Way Impacts
• Constructability
• Design Standard Conformance
• Cost
• Transportation Operations
• Funding Capability (City Contribution)

Evaluation Criteria Importance Rating

While each of these evaluation criteria had importance to the final decision, they were not each considered equal in their individual impact on the final concept selection. Each stakeholder had a different perspective on the relative importance of each criteria and this analysis process was designed to recognize these differences. The second step in the analysis process was to determine the "relative importance" of each evaluation criteria by weighing them on a scale.

The participants at the first Open House, March 31, 2010, were asked to provide a rating of the individual criteria. The results of that effort was accumulated with several other community groups. The "weighing" process is the cumulative judgment of the relative importance of each project criteria, as provided by all participants.

Selecting a Preferred Alternative

At the September 7, 2010 City Council meeting, the City's consultant, Omni-Means, Ltd, presented the Concept Selection Report and Appendices. The Report provided the detailed analysis of the evaluation and scoring process for each concept. The Report findings indicated that Concept 4A ranked as the highest scoring alternative based on the Concept Analysis Process outlined above.

After hearing public comment and considering all of the facts presented by City staff and the consulting team, the City Council voted to select Concept 2A as the locally preferred alternative. This Concept will rehabilitate the bridge in place and continue its use as a vehicular bridge. For a detailed layout of each concept considered, view the Refined Project Concepts.

Documents

• Concept Selection Report (posted 09/01/10)
• Concept Selection Report Appendices (posted 09/01/10)
• Refined Project Concepts