Level 2 Evaluation Criteria

The Level 2 evaluation expanded the measures for each of the criteria from Level 1 screening and provided a method for comparing design concepts to support the selection of the preferred alternative.

US 6/Wadsworth Interchange

Four interchange design concepts were studied in the second level of evaluation. The design concepts were rated as “good,” “fair,” or “poor” on 20 criteria related to design and safety features, mobility and traffic operations, local impacts, environmental impacts, costs, and implementation elements.

Some of the criteria weighed more heavily in the selection of a preferred alternative than others. For example, improving safety is a high priority, and criteria related to safety were therefore considered high priority. The four interchange concepts performed similarly on many of the criteria, including some of the highest priority criteria. The comparable performance of the concepts did not immediately indicate a clear preferred alternative for the interchange.

To better differentiate the design concepts from one other, the project team determined which criteria were the primary means of differentiating the concepts, and of those, which were the highest priority, based on the purpose and need of the project and the opinions voiced by the public at the February 2008 public meeting. The highest priority distinguishing criteria were, in order of importance: interchange capacity, pedestrian and bicycle crossings, corridor travel time, and cost.

After detailed evaluation of all 20 criteria, including the distinguishing criteria, the Tight Diamond with Loop was determined to best balance transportation needs with environmental and community impacts. For example, the Tight Diamond with Loop performs second best on the highest priority criterion, interchange capacity, while requiring significantly fewer relocations than the Partial Cloverleaf concept, which ranked best on interchange capacity.

The results of the Level 2 evaluation led to the selection of the Tight Diamond with Loop as the preferred alternative for improvements to the US 6 and Wadsworth Boulevard interchange.

Wadsworth Boulevard

The Wadsworth Boulevard preferred alternative consists of six travel lanes, a raised median, and sidewalks. This preferred alternative was identified during the Level 1 fatal flaw screening as the only concept that met project purpose and need. The alternative was, therefore, not compared against other design concepts in the Level 2 evaluation.