I-10 Twin Peaks Traffic Interchange, Environmental Assessment

Draft Environmental Assessment October 2005
Table 2-1. Comparison of 2030 Average Daily Traffic Volumes for Selected Roadway
Segments With and Without Twin Peaks Road TI .................................................... 2-5
Table 3-1. Existing and Proposed I-10 and Frontage Road Drainage Structures .......... 3-23
Table 3-2. Proposed Twin Peaks Road and Linda Vista Boulevard Drainage
Structures ................................................................................................................. 3-23
Table 3-3. Existing and Proposed Channels Serving I-10 and Frontage Roads ............ 3-25
Table 4-1. Proposed Property Acquisitions ..................................................................... 4-3
Table 4-2. Proposed Additional Drainage Easements ..................................................... 4-4
Table 4-3. Special Status Wildlife Species.................................................................... 4-27
Table 4-4. Special Status Plant Species ......................................................................... 4-34
Table 4-5. National and State Ambient Air Quality Standards ..................................... 4-46
Table 4-6. 2002 Monitoring Data from Coachline Site compared to NAAQS ............. 4-47
Table 4-7. Traffic Noise Monitoring Results..................................................................... 4-50
Table 4-8. Noise Mitigation Evaluation Summary........................................................ 4-62
Table 4-9. NRHP Eligibility Recommendations of Recorded Sites.............................. 4-74
Table 4-10. 2000 Selected Census Data ........................................................................ 4-79
Table 6-1. Summary of Environmental Assessment........................................................ 6-1
List of Figures
Figure 1-1. Project Location ............................................................................................ 1-2
Figure 1-2. Study Area..................................................................................................... 1-3
Figure 2-1. Levels of Service........................................................................................... 2-4
Figure 3-1. Typical Roundabout Interchange .................................................................. 3-3
Figure 3-2. Typical Diamond Interchange....................................................................... 3-3
Figure 3-3. Typical Single Point Urban Interchange....................................................... 3-3
Figure 3-4a. Alternative Alignments – North Alignment Alternative............................. 3-7
Figure 3-4b. Alternative Alignments – Center Alignment Alternative ........................... 3-7
Figure 3-4c. Alternative Alignments – South Alignment Alternative............................. 3-8
Figure 3-5. No Build Alternative................................................................................... 3-10
Figure 3-6. Preferred Alternative................................................................................... 3-11
Figure 3-7. Proposed Twin Peaks Road Typical Section .............................................. 3-12
Interstate 10 Traffic Interchange at
Twin Peaks/Linda Vista
iv
Project No.: NH-010-D (AIW)
TRACS No.: 10 PM 236 H5838 01D