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 />
connecting roadway sections on gravel<br />
fill) ; construction of the Anchorage<br />
Approach Alternative, a road below the<br />
bluff, around Cairn Point, <strong>and</strong> east of<br />
the Port of Anchorage (POA); <strong>and</strong><br />
construction of a cut-<strong>and</strong>-cover tunnel<br />
under Government Hill. A toll plaza <strong>and</strong><br />
lanes will also be included in the initial<br />
construction. The southeast end of the<br />
project in Phase 1 would connect to the<br />
A-C Couplet by way of Loop Road.<br />
Phase 2 construction would include full<br />
build-out to four lanes in the Mat-Su,<br />
expansion of the Crossing to four lanes,<br />
<strong>and</strong> extension of the project to the Ingra-<br />
Gambell Couplet by way of a bridge<br />
structure (the Ingra-Gambell Viaduct)<br />
across the Ship Creek rail yard.<br />
The timing of the need for elements<br />
described in Phase 2 is based on the best<br />
available traffic modeling <strong>and</strong> economic<br />
information available at this time. As an<br />
example, traffic studies have shown that<br />
the A-C Couplet currently has capacity<br />
available for additional traffic until<br />
about 2023. When traffic increases to the<br />
point that additional capacity would be<br />
required, Phase 2 would be constructed.<br />
It should be noted that if traffic grows<br />
faster than anticipated, elements<br />
described for Phase 2 could be<br />
constructed earlier <strong>and</strong> conversely, if<br />
traffic grows slower than anticipated,<br />
the need for additional capacity could<br />
occur later than currently anticipated.<br />
Moreover, based on constructability or<br />
project economics, certain elements<br />
from Phase 2 (e.g. initial four-lane<br />
construction of portions of the roadway<br />
or bridge or full construction of the<br />
tunnel under Government Hill) could<br />
occur as part of Phase 1.<br />
Description of the Recommended<br />
Alternative<br />
The FHWA identified the following<br />
alternative as the Preferred Alternative<br />
in the Draft EIS:<br />
• Northern Access – Degan Alternative<br />
or Erickson Alternative (with the<br />
Southern Alignment, 8,200-foot<br />
bridge length, <strong>and</strong> cut-<strong>and</strong>-cover<br />
tunnel under Degan Street or Erickson<br />
Street)<br />
The FHWA has identified the following<br />
alternative as the Recommended<br />
Alternative in the Final EIS:<br />
• Northern Access – Erickson Alternative<br />
(with the Southern Alignment,<br />
8,200-foot bridge length, <strong>and</strong> cut<strong>and</strong>-cover<br />
tunnel under Erickson<br />
Street)<br />
The Recommended Alternative for the<br />
KAC Project is a roadway <strong>and</strong> bridge<br />
crossing of <strong>Knik</strong> <strong>Arm</strong>, with roadway<br />
connections between Mat-Su <strong>and</strong><br />
Anchorage. The Recommended<br />
Alternative is displayed, from the Mat-Su<br />
to Anchorage, in the series of maps in<br />
Exhibits S-4 to S-14, beginning on page<br />
S-21. Exhibit S-4 provides a key to the<br />
location of each exhibit in this series.<br />
The following subsections describe the<br />
Recommended Alternative in more detail<br />
according to 1) its three geographical<br />
sections (Mat Su approach, Crossing,<br />
<strong>and</strong> Anchorage approach) <strong>and</strong> 2) its two<br />
phases of construction.<br />
Mat‐Su Approach<br />
The Draft EIS identified the Northern<br />
Access Alternative as the preferred Mat-<br />
Su Approach Alternative, <strong>and</strong> it is<br />
retained as the Recommended<br />
Alternative. As noted in Exhibits S-5 to<br />
S-8, the roadway will begin at the<br />
intersection of Point MacKenzie Road<br />
<strong>and</strong> Burma Road <strong>and</strong> follow the existing<br />
road alignment south about 9.5 miles<br />
until it reaches the boundary of the Port<br />
S-8