3.0 Affected Environment - Knik Arm Bridge and Toll Authority

Knik Arm Crossing DraftFinal EIS
Affected Environment
the Municipality of Anchorage created the Anchorage Metropolitan Area Transportation
Study (now called Anchorage Metropolitan Area Transportation Solutions) (AMATS),
whose responsibility is to carry out transportation planning and programming and air quality
conformity in Anchorage. AMATS is required, under the Transportation Equity Act for the
21st Century (TEA21), to develop and update an LRTP every 3 years and a transportation
improvement program (TIP) every 2 years. The LRTP includes major roads, transit,
multimodal, and intermodal facilities that operate as an integrated metropolitan transportation
system. The Anchorage LRTP was adopted in December 2005, and some of the projects in
the plan are discussed in this section. More information about AMATS can be found in
Section 3.1.
Natural resources and geographic features have required integration of the region’s various
transportation modes to meet the transportation needs of businesses and residents of
Southcentral Alaska. Because Anchorage is distant from the contiguous 48 states,
transportation to and from the Study Area is based as much on water and air transportation as
it is on land-based transportation. Within the boundaries of the area for which AMATS is
responsible, transportation planning plays a major role in effecting successful
implementation of a safe, efficient transportation system that can support the future economic
vitality of the metropolitan area; increase accessibility and mobility options; protect and
enhance the environment; and enhance the integration and connectivity of the transportation
system, across and between modes, for both people and freight.
Although Anchorage and the Mat-Su support transit and other transportation modes, the
private automobile is the primary mode for day-to-day transportation. Figure 3.10 shows the
regional transportation system, including rail lines, ports, major airports, and the regional
highway network. Marine vessel routes are shown in Figure 3.11.
3.2.2.1 Vehicular travel
Roadways in the Study Area serve local, regional, and statewide traffic. The system is made
up of both urban and rural roads. Traffic volumes range from very low on local and rural
roads to very high on major highways and some urban roads. Performance ranges from
excellent to unacceptable, with at-grade intersections generally contributing to the greatest
congestion-related problems.
Roadway and intersection performance and congestion can be measured 1) by the average
daily traffic (ADT), a measure of the number of vehicles using the facility, which can then be
compared to the lane-miles available to yield a volume-to-capacity ratio (“V/C,” the ratio of
the volume of traffic using a facility in a given time period to the capacity of the facility) or
2) by level of service (LOS). LOS is a term used to qualitatively describe the operating
conditions of a roadway or intersection based on the ratio of traffic volume to the design
capacity of the facility in consideration of a variety of factors such as speed, travel time,
maneuverability, delay, and safety.
12/18/07 Page 3-39