I-10 Twin Peaks Traffic Interchange, Environmental Assessment

Affected Environment and Environmental Impacts October 2005
A bridge carrying pedestrians and bicyclists over Twin Peaks Road was considered
also. The bridge concept had a number of disadvantages that resulted in
elimination of its consideration. These included: cost; privacy and security of
neighboring properties; hydraulic issues resulting from the placement of
embankment and bridge piers within the floodway; visual impacts to neighboring
properties; and, difficulty providing connections to the existing pedestrian and
bicycle facilities along Twin Peaks Road. Therefore, there were no prudent and
feasible alternatives to the use of the Santa Cruz Shared Use Path.
Use of 4(f) Resource: As discussed in Chapter 3, Alternatives, the Santa Cruz
Shared Use Path would be constructed prior to the construction of the preferred
alternative; therefore, the preferred alternative would incorporate approximately
500 feet of the adjacent path into the Twin Peaks Road extension, which is a use of
the resource under 4(f). The preferred alternative would incorporate less than one
percent of the path’s total length.
At-grade shared use path crossings of Twin Peaks Road were not recommended
because of potential vehicle conflicts; therefore, users of the shared use path would
be diverted along the Twin Peaks Road embankment approximately 850 feet east
of the shared use path’s alignment. To discourage pedestrian crossing of Twin
Peaks Road at the former alignment of the Santa Cruz River Shared Use Path, the
roadway’s center median would be fenced for approximately 100 feet in length.
This would direct path users to either cross under the Santa Cruz River Bridge or
at the nearest intersection to the west (Twin Peaks Road and Clover Road) using
the existing sidewalk and shared use lanes on Twin Peaks Road. Although
pedestrians and bicyclists would be diverted, the preferred alternative would not
impair the use of the remaining 4(f) property for its intended purpose.
Although noise levels in this area would increase with the preferred alternative, the
increase would not cause sound levels to exceed FHWA’s NAC; therefore, no
constructive use of the resource would occur. Construction of the preferred
alternative would require temporary closure of the Santa Cruz River Shared Use
Path during roadway and bridge construction; however, an alternative alignment of
the Santa Cruz River Shared Use Path would be available during construction. As
a result, no use of the 4(f) property would occur.
The preferred alternative would provide a new connection across I-10 and the
Santa Cruz River; therefore, the preferred alternative would improve access to this
4(f) resource.
Measures to Minimize Harm: Although the Santa Cruz River Shared Use Path
would be closed during construction, an alternative alignment would be provided
by diverting path users westward on Twin Peaks Road to the intersection of Twin
Peaks Road and Clover Road. This crossing location would remain after
construction is completed; therefore, no loss of access to the 4(f) property would
occur during construction.
The preferred alternative would divert pedestrians and bicyclists from the existing
alignment of the Santa Cruz River Shared Use Path. This diversion was necessary
Interstate 10 Traffic Interchange at
Twin Peaks/Linda Vista
4-93
Project No.: NH-010-D (AIW)
TRACS No.: 10 PM 236 H5838 01D