FEIS Summary - Knik Arm Bridge and Toll Authority

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Knik Arm Crossing Final EIS Summary connecting roadway sections on gravel fill) ; construction of the Anchorage Approach Alternative, a road below the bluff, around Cairn Point, and east of the Port of Anchorage (POA); and construction of a cut-and-cover tunnel under Government Hill. A toll plaza and lanes will also be included in the initial construction. The southeast end of the project in Phase 1 would connect to the A-C Couplet by way of Loop Road. Phase 2 construction would include full build-out to four lanes in the Mat-Su, expansion of the Crossing to four lanes, and extension of the project to the Ingra- Gambell Couplet by way of a bridge structure (the Ingra-Gambell Viaduct) across the Ship Creek rail yard. The timing of the need for elements described in Phase 2 is based on the best available traffic modeling and economic information available at this time. As an example, traffic studies have shown that the A-C Couplet currently has capacity available for additional traffic until about 2023. When traffic increases to the point that additional capacity would be required, Phase 2 would be constructed. It should be noted that if traffic grows faster than anticipated, elements described for Phase 2 could be constructed earlier and conversely, if traffic grows slower than anticipated, the need for additional capacity could occur later than currently anticipated. Moreover, based on constructability or project economics, certain elements from Phase 2 (e.g. initial four-lane construction of portions of the roadway or bridge or full construction of the tunnel under Government Hill) could occur as part of Phase 1. Description of the Recommended Alternative The FHWA identified the following alternative as the Preferred Alternative in the Draft EIS: • Northern Access – Degan Alternative or Erickson Alternative (with the Southern Alignment, 8,200-foot bridge length, and cut-and-cover tunnel under Degan Street or Erickson Street) The FHWA has identified the following alternative as the Recommended Alternative in the Final EIS: • Northern Access – Erickson Alternative (with the Southern Alignment, 8,200-foot bridge length, and cutand-cover tunnel under Erickson Street) The Recommended Alternative for the KAC Project is a roadway and bridge crossing of Knik Arm, with roadway connections between Mat-Su and Anchorage. The Recommended Alternative is displayed, from the Mat-Su to Anchorage, in the series of maps in Exhibits S-4 to S-14, beginning on page S-21. Exhibit S-4 provides a key to the location of each exhibit in this series. The following subsections describe the Recommended Alternative in more detail according to 1) its three geographical sections (Mat Su approach, Crossing, and Anchorage approach) and 2) its two phases of construction. Mat‐Su Approach The Draft EIS identified the Northern Access Alternative as the preferred Mat- Su Approach Alternative, and it is retained as the Recommended Alternative. As noted in Exhibits S-5 to S-8, the roadway will begin at the intersection of Point MacKenzie Road and Burma Road and follow the existing road alignment south about 9.5 miles until it reaches the boundary of the Port S-8
Knik Arm Crossing Final EIS Summary MacKenzie District (see southern edge of map in Exhibit S-7), where an intersection will be constructed to allow controlled access to the port. At the western end of the Port MacKenzie District, the roadway will diverge from the existing Point MacKenzie Road and traverse the uplands north of Lake Lorraine, heading in a southerly direction to the bluff line, and then ending on the eastern side of the Port MacKenzie District in an area approximately 7,200 feet north of Port MacKenzie Dock and 1,500 feet south of Anderson Dock. Before reaching the shoreline, a toll plaza and intersection would be constructed to control access to and from Port MacKenzie. The existing Port MacKenzie Road on the Mat-Su side currently provides one travel lane in each direction. The Mat-Su Borough is scheduled to upgrade the existing Point MacKenzie Road in 2008 independent of the KAC Project. Phase 1 construction will include required roadway improvements and development of the new alignment connection to the bridge approach. Phase 2 construction would upgrade the Northern Access to a four-lane divided highway (providing two travel lanes in each direction) and will include frontage roads and a pedestrian pathway. The road right-of-way (ROW) will be designated “controlled access,” meaning that intersecting roads or driveways will be permitted only at limited points. ROW for Phase 2 construction would be purchased during Phase 1. This route will cross 28 land parcels, but will involve no residential or business acquisitions. Crossing The Draft EIS identified the Southern Alignment 8,200-foot Bridge Alternative as the preferred crossing alternative, and it is retained as the Recommended Alternative for crossing Knik Arm. As noted in Exhibit S-9 and S-10, to cross Knik Arm, the Recommended Alternative will begin at the shoreline on the Mat-Su side of Knik Arm between the Port MacKenzie Dock and Anderson Dock and reach the shoreline on the Anchorage side approximately 1 mile north of Cairn Point. The roadway will follow the Anchorage shoreline and western perimeter of Elmendorf Air Force Base (Elmendorf) at the bottom of the bluff to south of Cairn Point. Construction of this roadway section will include placement of as much as 2 miles of armor protected intertidal fill. The bridge will be pier-supported, with approach embankments. On opening day, the bridge will have a minimum of one lane in each direction. When travel demand would warrant, Phase 2 construction would expand the bridge to include two lanes in each direction along with a multiuse pathway. Anchorage Approach With information obtained from the Draft EIS review process, FHWA identified the Erickson Alternative as the Recommended Alternative for the Anchorage approach (Exhibits S-10 to S-14). From the vicinity of Cairn Point, the Anchorage approach will continue south, closely following the natural curvature of the shoreline. In the vicinity of the Cherry Hill bluff, the roadway will climb slightly on an area of fill supported by retaining walls at the base of the bluff to provide grade separation for security and operational purposes between the roadway and the edge of the POA property. From this point, the roadway will follow the alignment of Erickson Street to connect to the A-C Couplet (Phase 1) and then, when warranted by traffic volumes, to a new Ingra-Gambell Viaduct in Phase 2. Because the roadway will run close to sensitive areas, it will be isolated from military and POA operations by security fencing. All access to Elmendorf or Fort S-9
Page 1 and 2: Knik Arm Crossing Final Environment
Page 3 and 4: Exhibit S‐1. Final EIS Document O
Page 5 and 6: Knik Arm Crossing Final EIS Summary
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Page 15 and 16: Exhibit S‐22. Reasons for Preferr
Page 17 and 18: Findings, Compliance, and Permits E
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Page 33 and 34: The preliminary design includes pla
Page 35 and 36: Summary Initial Construction (Phase
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Knik Arm Crossing Final EIS Summary
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FEIS Summary - Knik Arm Bridge and Toll Authority

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