The document provides an overview of a proposed onramp project, including background on population growth and existing conditions, demand analysis, design considerations, environmental impacts, cost estimates, and alternatives. It finds that the projected population growth would not exceed the road's capacity, so a new interchange is not currently necessary, though improvements to existing roads could help alleviate more immediate issues. It recommends considering the alternatives rather than proceeding with the onramp project at this time.

2. OVERVIEW
• Introduction • Environmental Impacts
• Background • Cost Estimation
• Demand • Alternatives
• Design • Final
Recommendation

3. INTRODUCTION
PURPOSE
• County can determine proposed onramp’s necessity
• Helps County prioritize where the onramp fits in the
implementation of Community Plan (if it fits at all)
NOT A PROPOSAL

4. BACKGROUND
Population and Surrounding Land
Uses
• Existing population of 1,835
• Projected population of 5,182
• Surrounding land uses
• Currently: SF Residential & Commercial
• Community Plan will increase amount and types
of land

5. BACKGROUND
Existing Onramp Conditions
• Four connections to Highway 101
• Northern and Southern Mission
• 10th Street
• Cemetery Road

6. BACKGROUND
Existing Onramp Conditions
• Current Onramps are not ideal
• S. Mission southbound onramp enters into fast
lane
• 10th Street not a complete interchange
• Does not comply with Caltrans standards
• Lacks southbound onramp

7. BACKGROUND
Existing Onramp Conditions
• Cemetery Road:
• Drivers must travel over a mile to enter freeway
• No speed limit signs
• Treated as one, large onramp
• Prevalent cracking and deterioration in asphalted
pavement

8. BACKGROUND
Existing Onramp Conditions
Onramp Distribution:
• S. Mission is more popular despite safety concerns
Caltrans Traffic Volumes for 2008
Onramp/Direction Average Daily Trips
Cemetery Road/ SB On 850
S. Mission St./ SB On 1700
S. Mission St./ NB Off 1800
10th St./ NB Off 800
10th St./ SB Off 300

9. DEMAND
Social Demand
• Shorter travel distance preferred
• Safer conditions
• Cemetery Road treated as one, large onramp
• Reduces traffic off Cemetery Road
• Preferred for future residential development west of
Cemetery Road

10. DEMAND
Social Demand
• 87% community workshop feedback in favor of
improved onramp interchange

11. DEMAND
Technical Demand
• Ultimate goal to find Cemetery Road future Level
of Service (LOS)
• Trip generation based on land use and land use
area

12. DEMAND
Technical Demand
• Trip Generation
Total Trip Generation
Daily Trips AM Peak Hour PM Peak Hour AM In AM Out Pass By PM In PM Out Pass By
128,091 7,062 13,853 10,110 1,916 444 4,570 6,197 3,086
•Focus is on PM Out trips

13. DEMAND
Technical Demand
• Where are these trips going?
• How many are leaving San Miguel?
• Of these, how many are using Cemetery
Road?

14. DEMAND
Technical Demand
• Trip Distribution
Distribution Analysis
Distribution 2000 ADT 2003 ATD 2008 ATD Average
Northbound 24.09% 20.83% 22.15% 22.36%
Southbound 75.91% 79.17% 77.85% 77.64%
Southbound Distribution Analysis
Distribution 2000 ADT 2003 ATD 2008 ATD Average
Cemetery Road 42.31% 44.74% 33.33% 40.13%
South Mission 57.69% 55.26% 66.67% 59.87%

15. DEMAND
Technical Demand
• Level of Service
• Based on Transportation Research Board’s
Highway Capacity Manual (2000)
• Volume-Capacity Ratio
• Cemetery Road capacity at 1,600 vehicles
per hour per lane

16. DEMAND
Technical Demand
• Level of Service C Threshold
• To cross threshold of Level ofTrips Using Cemetery
# Trips Leaving San
LOS Service
#
C, trips leaving must
% Trips Leaving San Miguelabout 60% (v/c threshold at 0.71) Level of Service
at exceed Miguel Rd V/C Ratio
75 4,648 1,448 0.91 F
• 60% on the conservative side based on land
70 4,338 1,352 0.84 D
uses providing internal trips 1,255
65
60
4,028
3,718 1,158
0.78
0.72
D
D
• Range likely under 55%
55 3,408 1,062 0.66 C
50 3,099 965 0.60 C
45 2,789 869 0.54 C
40 2,479 772 0.48 B
35 2,169 676 0.42 B

17. DEMAND
Technical Demand
New interchange not necessary
Level of Service
# Trips Leaving San # Trips Using Cemetery
% Trips Leaving San Miguel Miguel Rd V/C Ratio Level of Service
75 4,648 1,448 0.91 F
70 4,338 1,352 0.84 D
65 4,028 1,255 0.78 D
60 3,718 1,158 0.72 D
55 3,408 1,062 0.66 C
50 3,099 965 0.60 C
45 2,789 869 0.54 C
40 2,479 772 0.48 B
35 2,169 676 0.42 B

18. DESIGN
Dimensions
• Length at 700 feet
• Average acceleration time and
necessary length to reach 65mph (465
feet)
• Distance at which drivers can clearly
see traffic on highway (additional 245 Cemetery
Road
feet)
• Consistent with northbound onramp
Cemetery
Road
Cemetery
Road
Cemetery
Road

19. DESIGN
Dimensions
• Width at 24 feet
• Based on Caltrans Highway Design
Manual
• 12 foot single lane width
• 8 foot paved right shoulder
• 4 foot paved left shoulder Cemetery
Road
Cemetery
Road
Cemetery
Road
Cemetery
Road

20. DESIGN
Additional Considerations
• Relocation of Cemetery Road
Intersection
• Based on Caltrans Highway Design
Manual
• At least 400 feet westward Cemetery
Road
Cemetery
Road
Cemetery
Road
Cemetery
Road

21. ENVIRONMENTAL IMPACTS
Air Quality
• Temporary rise in particulate matter
Habitat
• Threatened and endangered
species within 1 mile radius of San
Miguel
• San Joaquin Kit Fox – Not near
onramp site
• Soil: Legend
• Valuable agricultural soil may pose
as a constraint for development

22. ENVIRONMENTAL IMPACTS
Topography &
Hydrology
• Onramp site not affected
by topographical and
hydrological constraints
• Not within 100-year
floodplain
• Slope on project site
permits development
• Drainage ditch partially
paved over

23. COST ESTIMATION
• From numerous sources:
• Rene’ Walker, Office Engineer
• Colin Jones, Chief of Public Affairs
• Willow Road Interchange Project
• Cost • Caltrans Budget for
• $400 - $600 thousand District 5
• Considers construction, Highway Projects
labor, equipment, •$350-400 million
environmental review

24. ALTERNATIVES
Alternative Total Cost Extra Cost
10th Street Interchange Improvement $400,000 - $600,000 -
S. Mission Improvement $300,000 - $400,000 $65,000 / yr
Cemetery Road Improvement $195,200 -
Cemetery Road Improvement W/ Meter $495,200 - $ 595,200 $65,000 / yr
S.Mission & Cemetery Road Improvement $495,200 - $595,200 $65,000 / yr
No Build - -

25. RECOMMENDATION
• Consider alternatives
• Alleviates more immediate issues
• Demand not met

26. THANK YOU