I-10 Twin Peaks Traffic Interchange, Environmental Assessment

Affected Environment and Environmental Impacts October 2005
concrete block wall along Linda Vista Boulevard. To preserve views of the Santa
Catalina Mountains to the east, the residence’s eastern wall is constructed of
wrought iron. To mitigate traffic noise, a solid wall along the eastern side of the
property would be required. Because the home was constructed to preserve views
to the east, it is assumed that construction of a solid wall in this area would be
unacceptable to the property owner. In addition, the construction of a noise
mitigation wall would protect only this single isolated residence, which is not
considered reasonable by ADOT’s noise policy. For these reasons, this wall would
not be constructed; however, this decision would be discussed during the public
hearing for this project and during subsequent property owner meetings.
Receiver LVR8 – This receiver, on the southwest corner of Linda Vista Boulevard
and Albatross Drive, is predicted to experience traffic noise levels of 65 dBA.
According to STAMINA, the residence south of LVR8 was predicted to exceed
the NAC also; therefore, mitigation for these two residences was considered. A
reduction in traffic noise levels of 5 dBA was produced by a wall 256 feet in
length and 10 feet in height along Linda Vista Boulevard. This wall was estimated
to cost $51,200 and protect two residences. The cost per benefited receiver is
$25,600; therefore, this wall would be constructed.
Receivers LVR9 – LVR10 – These receivers, from the southeast corner of Linda
Vista Boulevard and Albatross Drive to the southwest corner of Linda Vista
Boulevard and Bald Eagle Drive, are predicted to experience traffic noise levels of
65 and 67 dBA, respectively. In addition to LVR9 and LVR10, an additional 6
residences would experience noise levels in excess of the NAC in this area. These
residences would be protected by a wall that begins 48 feet south of Linda Vista
Boulevard, moves north to Linda Vista Boulevard and then turns to the east for
500 feet. The 48-foot length would be 11.5 feet in height and the 500-foot length
would be 12 feet in height. The approximate overall cost for the wall would be
$131,040. The wall would protect only 7 of the 8 receivers in this area. LVR10
represents the clubhouse and community swimming pool for this subdivision,
which currently has a wrought iron fence on the east side to allow views of the
mountains. To reduce noise substantially at this location, the wall would be
required to wrap to the south in this area, which would result in blocking the
mountain views; therefore, extending the wall to the south would not occur;
however, this decision would be discussed during the public hearing for this
project and during subsequent property owner meetings. All homes in the area
would be benefited by the proposed wall. The cost per benefited receiver for this
wall would be $18,720; therefore, this wall would be constructed.
Receivers LVR11 – LVR12 – These receivers, from the southeast corner of Linda
Vista Boulevard and Bald Eagle Drive to the southwest corner of Linda Vista
Boulevard and Manatee Drive, are predicted to experience traffic noise levels of
67 and 69 dBA, respectively. In addition to LVR11 and LVR12, an additional 4
residences experience noise levels in excess of the NAC in this area. Although
several of these residences have an existing 6-foot wall that parallels Linda Vista
Boulevard, these homes are several feet lower in elevation than the roadway. All
Interstate 10 Traffic Interchange at
Twin Peaks/Linda Vista
4-60
Project No.: NH-010-D (AIW)
TRACS No.: 10 PM 236 H5838 01D