The study team worked collaboratively with partner agencies, stakeholders, and the public to apply a systematic alternative screening process. The process was designed to identify those concepts that best satisfy the study’s Purpose and Need and warrant additional study, while eliminating under-performing concepts. For the Draft Environmental Impact Statement (DEIS) , the process was broken down into three (3) screening levels. Those concepts that remained at the end of each consecutive level underwent increasingly rigorous analysis to determine which concept(s) best suited the Purpose and Need identified at the beginning of the study while minimizing environmental impacts. The end result was four freeway alternatives that were thoroughly evaluated for environmental impacts and possible mitigation measures. Following the DEIS, these freeway alternatives were revised to arterial alternatives based on updated traffic information. The arterial alternatives, their impacts, and associated mitigation measures are described in detail within the Final Environmental Impact Statement (FEIS).
LEVEL 1 SCREENING
The first level of screening considered concepts in the entire study area. Many of the concepts were taken from the 2001 Pyramid Corridor Management Plan and reconsidered alongside new concepts. The analysis consisted of qualitative Purpose and Need and fatal flaw analysis. System, transit, and lane type alternatives were considered in addition to roadway concepts. A total of thirty-four alternatives were considered and the results summarized in the Level 1 Screening Matrix. The roadway concepts are illustrated and summarized here.
LEVEL 2 SCREENING
The second level of screening was broken into two parts: Level 2A and Level 2B. The intent was to further reduce the number of feasible concepts in Level 2A through general traffic and environmental analysis so there remained a manageable number of concepts in Level 2B to apply conceptual engineering, more detailed traffic and environmental analysis. Level 2 focused solely on roadway concepts totaling eight in Level 2A and two in Level 2B. Click here to see the Level 2A Screening Matrix and here to see the roadway concepts illustrated and summarized. The Level 2B Screening Matrix can be found here.
LEVEL 3 SCREENING
Using the results of the Level 2 screening process, Level 3 focused on different alternatives of the remaining general roadway concept (H17). That concept being a conversion of Pyramid Highway to a freeway from Eagle Canyon/La Posada south and connecting to an east/west freeway that ultimately interchanges with US 395 at or near Parr Boulevard. The alternatives focused on system interchange locations with US 395, interchange and crossing locations in the Sun Valley area, freeway alignment options in the Pyramid Highway corridor south of Sparks Boulevard, and interchange configuration between Dolores Drive and Eagle Canyon/La Posada. The Level 3 roadway alternative screening process summary can be found here. In addition to roadway alternatives, supplemental alternatives that were carried forward from Level 1 screening were considered and further screened as well.
The various options that resulted from the Level 3 Screening process were packaged into a series of four distinct alternatives for analysis in the Draft EIS document. The various concepts could be mixed and matched to create other alternatives; however, four freeway alternatives were assembled to provide a reasonable yet manageable range of alternatives and resulting impacts. These alternatives were evaluated in the DEIS
Reduced traffic demand changed the type of highway facility needed; the Study team concluded that an arterial facility instead of a freeway facility could provide adequate capacity for the projected traffic volumes. While the alignments of the Arterial Alternatives evaluated in the FEIS are the same as the four freeway alternatives studied in the DEIS, the design modifications made after the DEIS resulted in project changes such as overall narrowing of the alternative footprints and eliminating certain previously-proposed grade-separated interchanges and all frontage roads along Pyramid Highway.
Maps showing these arterial alternatives, which are described below, are located in the Executive Summary and Chapter 2 of the FEIS, which can be downloaded by visiting the FEIS page . Maps of the Preferred Alternative can be downloaded here :
Arterial Alternative 1
Arterial Alternative 1 would consist of an alignment just west of the existing Pyramid Highway between the US 395 Connector and Highland Ranch Parkway. This alignment would be located just below the mountain ridgeline west of Pyramid Highway. Of the two alternative alignments through Sun Valley, Arterial Alternative 1 would follow the northern crossing and would include an interchange at Sun Valley Boulevard.
Arterial Alternative 2
Arterial Alternative 2 would consist of an alignment along the existing Pyramid Highway between the US 395 Connector and Sparks Boulevard/Highland Ranch Parkway. The US 395 alignment would follow the southern crossing of Sun Valley and would include an interchange at Sun Valley Boulevard.
Arterial Alternative 3
Arterial Alternative 3 would consist of an alignment along the mountain ridgeline between the US 395 Connector and Sparks Boulevard/Highland Ranch Parkway. This alignment would not include any interchanges between Disc Drive and Highland Ranch Parkway. The US 395 alignment would follow the southern crossing of Sun Valley and would include an interchange immediately west of Sun Valley Boulevard.
Arterial Alternative 4
Arterial Alternative 4 would consist of an alignment along the existing Pyramid Highway between the US 395 Connector and Sparks Boulevard/Highland Ranch Parkway, with a northern crossing of Sun Valley and an interchange immediately west of Sun Valley Boulevard.