HomeMy WebLinkAbout2012-01-18 Packet - Appellant_Concerns With Proposed Traffic MitigationConcerns With Traffic Impact Analysis
Mitigation Sketches Omit Required Geometric Details
Sketches Omit Geometric Constraints
Mitigations Assume Unapproved Geometrics
When Above Is Considered, Mitigations Won’t Fit Or Won’t Perform As Claimed
Base Traffic Counts Taken In Low Traffic Month and Study Omits Impacts of Compound Queue
Geometric Concerns
Actual scale size of roundabouts
Splitters
Bay tapers
Lane transitions and needed lanes
Sidewalks, sideslopes or retaining walls
Bypass Lanes
Grade
Left Turn Queues At Airport Park Overflow Their Storage
[1] All scenarios are for PM peak hour for westbound left turn lanes on Talmage at Airport Park under proposed mitigation for this intersection and with Roundabout A mitigation at Talmage
with southbound US 101 ramps. B= Baseline, F= Future, +P= plus Project, +DC = plus Discount Club
[2] Combined queue storage length of both westbound left turn lanes with proposed Talmage-Airport Park intersection mitigation as assumed in DEIR traffic study calculations. All storage
and queue values in feet.
[3] Actual available storage in both westbound left turn lanes with proposed Talmage-Airport Park intersection mitigation and Roundabout Option A.
[4] Per DEIR Appendix B, Appended Queuing & Blocking Reports. The 95th %ile queue ordinarily defines the queue length to be accommodated for design purposes and is often referred-to
as the “design queue”.
[5] Length of 95th %ile queue in excess of actual queue storage with Roundabout A.
[6] Average length of all queues that build in the subject left turn lanes, considering each signal cycle occurring in the peak hour per DEIR Appendix B, Appended Queuing & Blocking
Reports.
[7] Length of Average queue in excess of actual queue storage with Roundabout A.
February Traffic Count Base Understates Traffic Impacts
Caltrans Northern California US 101 Data Shows Feb Traffic 7% Below Annual Avg. & 12.4% Below Avg. of Busiest 6 Mos.
Trip Generation, 8th Edition Shows Feb Shopping Center Traffic Is Only 78.1% of Annual Avg. and Is Lowest Month of Year
Normal Splitter Islands