FEIS Summary - Knik Arm Bridge and Toll Authority
FEIS Summary - Knik Arm Bridge and Toll Authority
FEIS Summary - Knik Arm Bridge and Toll Authority
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<strong>Knik</strong> <strong>Arm</strong> Crossing Final EIS<br />
<strong>Summary</strong><br />
Exhibit S‐19. Transportation Features <strong>and</strong> Traffic Flow Characteristics (continued)<br />
Degan Alternative<br />
Erickson Alternative<br />
(Recommended Alternative)<br />
Phase 2<br />
Phase 2 modifies Phase 1 construction to allow a<br />
connection to a viaduct traversing the Ship Creek<br />
industrial area to tie into the future Glenn-Seward<br />
Highway-to-Highway Connection (proposed by the<br />
Municipality of Anchorage in its 2025 LRTP) at the<br />
Ingra-Gambell Couplet <strong>and</strong> 3rd Avenue (EIS<br />
Figure 2.35).<br />
The signalized intersection constructed in Phase 1 is<br />
removed <strong>and</strong> East Loop Road is elevated to cross over<br />
the Degan Alignment to facilitate free-flow traffic from<br />
the proposed KAC bridge to the Ingra-Gambell Couplet.<br />
Government Hill <strong>and</strong> A-C Couplet through-traffic has<br />
access to or from the KAC bridge by way of ramps on<br />
the north side of the tunnel.<br />
Mat Su <strong>and</strong> A-C Couplet through-traffic uses Government<br />
Hill surface streets <strong>and</strong> a signalized intersection at Loop<br />
Road <strong>and</strong> Hollywood Drive to continue down East Loop<br />
Road <strong>and</strong> gain access to the A-C Couplet.<br />
Traffic traveling north from the Ingra-Gambell Couplet<br />
uses ramps to gain access to Government Hill.<br />
Phase 2 necessitates an additional tunnel with four<br />
more lanes. The tunnel expansion (two additional<br />
parallel tunnels with six total lanes needed for Phase 2)<br />
then connects to the proposed viaduct that traverses<br />
the Ship Creek industrial area <strong>and</strong> ties into the future<br />
Glenn-Seward Highway-to-Highway Connection<br />
(proposed by the Municipality of Anchorage in its<br />
2025 LRTP) at the Ingra-Gambell Couplet intersection<br />
with 3rd Avenue.<br />
Some alignment modifications of the initial<br />
construction <strong>and</strong> additional ramp construction are<br />
necessary to allow free-flow of traffic to the termini at<br />
the A-C <strong>and</strong> Ingra-Gambell Couplets.<br />
Government Hill traffic gains access to or from the<br />
KAC bridge by way of ramps on the north side of the<br />
tunnel. A-C Couplet through-traffic has access to the<br />
KAC bridge through the two-lane, two-way, cut–<strong>and</strong>cover<br />
tunnel, bypassing Government Hill.<br />
Mat Su <strong>and</strong> A-C Couplet through-traffic uses the<br />
free-flow condition, two-lane, two-way tunnel through<br />
Government Hill to gain access to the A-C Couplet.<br />
Traffic heading north from the Ingra-Gambell Couplet<br />
does not have direct access to Government Hill.<br />
Northbound Government Hill traffic needs to travel<br />
west to the A-C Couplet <strong>and</strong> then use ramps from the<br />
A-C Couplet to gain access to Government Hill.<br />
The existing lanes of the southbound East Loop Road<br />
at Hollywood intersection are not changed from what<br />
presently exist—two lanes, with the left lane having a<br />
left turn or through-movement <strong>and</strong> the right lane<br />
allowing a right turn onto Erickson Street or a throughmovement.<br />
The alternatives’ locations were selected<br />
because their topographic <strong>and</strong> site<br />
conditions would be conducive to<br />
constructing a cut-<strong>and</strong>-cover tunnel less<br />
than 800 feet long (a controlling design<br />
feature). A cut-<strong>and</strong>-cover tunnel is<br />
proposed to minimize impacts to the<br />
Government Hill community.<br />
The Draft EIS did not identify either<br />
Anchorage approach alternative as<br />
preferred, <strong>and</strong>, during the Draft EIS<br />
review phase, FHWA requested comment<br />
on the Anchorage approach alternatives<br />
to assist the agency in selecting an<br />
alternative.<br />
Comparison of Traffic Characteristics<br />
Exhibit S-19, on pages S-12 through<br />
S-13, describes the alternatives in more<br />
detail by comparing the key features <strong>and</strong><br />
S-13