FEIS Summary - Knik Arm Bridge and Toll Authority

Knik Arm Crossing Final EIS
Summary
Exhibit S‐20. Degan Alternative: Advantages and Disadvantages
Degan Alternative
Advantages
Originally designed to traverse Government Hill at its narrowest section, thereby minimizing impacts to
Government Hill.
• During the Draft EIS process and discussions with the Alaska Railroad Corporation (ARRC), it was identified
that the viaduct across the Ship Creek rail yard (Phase 2 alignment) needed to be rerouted so that pier locations
would not adversely affect rail operations. As a result, the advantages of this alternative were diminished. With
the Degan alignment shifted to the east, additional impacts to residences and Sunset Park resulted.
Furthermore, the revised Degan Alternative required roadway geometrics that were less desirable than the
Erickson Alternative.
Disadvantages
• Access through Government Hill would require a stop and a turn at the intersection of East Loop Road,
adversely affecting the neighborhood with additional surface traffic and opportunities for vehicle-pedestrian
conflicts.
• The signalized intersection at East Loop Road and Degan Street is located on a curve and a hill, making stopping
difficult.
• This alternative would require 400 feet more ROW than the Erickson Alternative at its widest point.
• Geometrics to connect to the Ingra-Gambell Couplet are more circuitous.
• This alternative would take 65 percent of Harvard Park, 59 percent of Sunset Park, and would adversely affect
the Anchorage Square & Round Dance Club.
Exhibit S‐21. Erickson Alternative: Advantages and Disadvantages
Erickson Alternative
(Recommended Alternative)
Advantages
• The Erickson Alternative allows free-flow of traffic through a cut-and cover tunnel, avoiding local streets.
• This alternative reduces ROW requirements by 400 feet (compared with the Degan Alternative) for ramps north
of Government Hill.
• The geometrics of the Erickson Street alignment connecting to the Ingra-Gambell Couplet are more direct.
• Government Hill would have improved access to downtown and to the Mat-Su through use of both north and
south ramps.
Disadvantages
• Phase 2 expansion would require new tunnels, causing a second period of construction impacts to Government
Hill residents.
• Construction management and traffic control would be challenging because construction activities would
disrupt the main route through Government Hill and to the military bases.
• The Erickson Alternative would adversely affect the Government Hill Urban Renewal Historic District, including
three contributing structures, and would take 2 percent of Harvard Park and 31 percent of Sunset Park.
• The cost for Phase 1 would be $6.4 million more than that for the Degan Alternative and the cost for Phase 2
would be $16.4 million more than that of the Degan Alternative.
flow of traffic under each alternative.
Exhibit S-18, on page S-35, also
facilitates understanding of the two
alternatives’ relative traffic flows.
Comparison of Impacts
As Exhibit S-17, on page S-34, shows (and
the EIS discusses in detail), both
Anchorage approach alternatives are
associated with impacts to residential,
commercial, and industrial land; and
Section 4(f) properties (Harvard and
S-14