US-101
PROJECT SITE
SOUTH SAN
FRANCISCO
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San Mateo Countywide Sustainable Streets Master Plan
Grand Avenue South San Francisco
South San Francisco has a goal to revitalize, improve,
and support the downtown area. The City plans to
improve circulation and connectivity and to create an
attractive and vibrant pedestrian environment along the Grand Avenue corridor. This sustainable street concept
envisions a reconfiguration of Grand Ave between Maple
Ave and Linden Ave with increased pedestrian spaces
and integrated stormwater management within green
infrastructure facilities.
This project would realign parking from angles to parallel on both sides of Grand Ave to allow space for a bike
lane and increased pedestrian areas. The parking lane is proposed to be permeable pavement which will provide
infiltration of runoff. The mid-block area is proposed to include a wider sidewalk and colored paving within the
driving lanes to promote traffic calming and increased
pedestrian safety. Sidewalk and pedestrian spaces will be installed as boardwalks overlaying bioretention planters.
This will provide large stormwater facilities that can
manage roadway and sidewalk runoff while preserving
space for pedestrian use along the busy commercial and
mixed-use corridor. Street trees will be integrated along the parking lane and within the pedestrian boardwalk.
A total of 5,600 square feet of permeable pavement is
proposed and a total of 10,200 square feet of bioretention planter integrated in boardwalks are proposed. These
are estimated to capture stormwater runoff from
approximately 1.2 acres of roadway, providing capture of
2.5 acre-feet of runoff per year. This project is expected to retain 68% or runoff.
Concept Description
Site Characteristics
In Priority Development Area
Yes
Watershed
Colma Creek
Green Infrastructure
Performance
Drainage Management Area
1.2 ac
Annual Runoff Captured
2.5 ac-ft
Bioretention Area / Storage Volume
10,200 sf / 0.35 ac-ft
Permeable Pavement Area / Storage
Volume
5,600 sf / 0.08 ac-ft
Active Transportation
Performance
Change in Bicycle Level of Traffic
Stress (LTS)
LTS 4 to LTS 3
Increase in % Likely Bicyclist Usage
11%
Key Transportation Benefits
» Reduced pedestrian crossing
distance
» Increased pedestrian space
» Traffic calming
» Added bike lane
[ ]
0 20’ 40’ 60’ 80’
A
B
C E
D F
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Typical Cross Section a-a: Grand Avenue
6’
Bike Lane
6’
Bike Lane
22’
Grand Avenue
12’
Bioretention
Planter
12’
Bioretention
Planter
11’
Sidewalk
11’
Sidewalk
A
D
A
A
E
D
F
F
C
C B
B
a b
a b
GRAND AVENUE
MAPLE AVENUE
LINDEN AVENUE
Concept Site Plan Detail: Grand Avenue, South San Francisco
KEY SITE IMPROVEMENTS
Proposed bioretention planter
Proposed suspended pavement
over bioretention planter
Proposed permeable pavement
Proposed bike lane
Proposed plaza crossing
Existing bus stop Existing
Pedestrian
Space
Added
Pedestrian
Space
Parking and
Roadway Area
Site Elements
Tree dividers between parking stalls Paver sidewalk and furnishing zone Flex-use parking lane converting to outdoor seating Kevin Robert Perry, Urban Rain design Kevin Robert Perry, Urban Rain design Kevin Robert Perry, Urban Rain designPermeable pavement parking and step-out zone Kevin Robert Perry, Urban Rain design E-76
Grand Avenue South San Francisco
Typical Cross Section b-b: Grand Avenue
6’
Bike Lane
6’
Bike Lane
22’
Grand Avenue
8’
Permeable
Pavement Parking
8’
Permeable
Pavement Parking
15’
Sidewalk
15 Sidewalk
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Site Elements
Concept Perspectives
Downtown street plaza space Downtown street plaza space Boardwalk over bioretention basin as sidewalk space Boardwalk & paver sidewalk space with protective bollards Kevin Robert Perry, Urban Rain Design Kevin Robert Perry, Urban Rain Design Kevin Robert Perry, Urban Rain Design Kevin Robert Perry, Urban Rain Design Existing condition, Grand Ave between Maple Ave and Linden Ave Proposed condition This is a planning-level cost estimate ($2020) for design and construction. Soft costs for City administration and project management and post-construction operations and maintenance are not included.
Other factors that may affect the cost of future construction include escalation and market conditions. E-78 Increased Trees
Shade for walking comfort
Heat and carbon emission reduction
Neighborhood Beautification
Increased vegetation
Provide engaging streets to walk on
Reestablishes Natural Hydrology
Bioretention planters capture and infiltrate
stormwater
Project Benefits
Groundwater Recharge
Recharge of the Westside Groundwater
Basin
Walkability & Safety
Curb extensions for safer street crossing
Connection to commercial areas
Prioritize Non-Motorized Users
Promote more active transportation
Planning-Level Cost Estimate
Bikeability & Safety
Increased protected bike lanes
Increased bike-share roads
Bike Network
Part of larger network for connectivity
Promote biking with more connectivity
Grand Avenue South San Francisco
DESCRIPTION UNIT COST UNIT COST QUANTITY SUBTOTAL
Utilities Protection/Relocation $120,000 LS 1 $120,000
Sawcutting Pavement $12 LF 2,600 $31,200
Concrete Demo, Excavation & Offhaul $11 SF 15,600 $171,600 Planter Excavation & Offhaul $70 CY 980 $68,600
Planter Curb & 36" Sidewalls $160 LF 620 $99,200
Planter Curb & Gutter & 36" Sidewalls $180 LF 600 $108,000 Bio-soil Media $250 CY 390 $97,500
Underdrains $6 SF 2,730 $16,400
Drain Rock Subbase $160 CY 490 $78,400
Bioretention Plantings & Mulch $25 SF 1,670 $41,800
Storm Drain Connections $7,500 EA 4 $30,000
Bioretention Curb Inlet $1,500 EA 10 $15,000
Permanent Tree Protection $165 LF 192 $31,700
Flush Curb Ribbon $60 LF 1,570 $94,200
Permeable Pavement $25 SF 6,020 $150,500
Bikelane Striping $12 SF 5,100 $61,200
Irrigation System $13,240 EA 6 $79,400
Traffic Sign Relocation $900 EA 6 $5,400
Trees $1,500 EA 22 $33,000
Boardwalk Surfacing $50 SF 5,320 $266,000
Plaza Road Paint $5 SF 5,500 $27,500
CONSTRUCTION SUBTOTAL $1,627,000
Traffic Control $81,350
Mobilization (10% construction) $163,000
Contingency (30% construction) $488,000
Design Fees (15% total) $354,000
TOTAL PROJECT COST (DESIGN + CONSTRUCTION) $2,713,000
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This project concept is presented for discussion only. This project concept is planning-level and subject to revision as additional information becomes available. Factors to be considered during design of this project include but are not limited to the following:
» Infiltration Potential. The hydrologic soil group is unknown along Grand Ave. A geotechnical investigation will be conducted during design development, including site-specific borings and infiltration tests, to ensure facilities are designed appropriately. This design incorporates bioretention below boardwalk areas within the sidewalk resulting in a large amount of facility area relative to the roadway drainage area. Therefore, bioretention facilities will likely be able to manage roadway runoff without the need for underdrains even if slow draining soils are present on site.
» Utility Conflict. Initial utility assessments were conducted for sanitary sewer, storm sewer, and water mains.
Bioretention facilities are proposed in configurations that minimize disruption of sewer and water lines. Other utilities such as power and gas were not available for consideration during the development of this concept and should be assessed during design development.
» Street Trees. Trees are proposed within the parking lane. These will be protected with curbs or fencing. They are proposed to divide every two parking spots. The trees will provide shade and assist in stormwater management within the roadway.
» Maintenance. Bioretention planters located under pedestrian boardwalks will require minimal maintenance as they will not be planted and smaller exposed bioretention planters will serve as the inlet and outlet of these systems. The inlet planters will capture the majority of the sediment load and prevent the downstream planters below the boardwalk from needing frequent maintenance.
Additional Considerations