presentation: sidewalks and street trees 09.20.2010
TRANSCRIPT
Sidewalks and Street TreesAlong Local Streets in
Residential Communities
Goal: Sustainable Communities, Safe Sidewalks and Healthy Trees
Issues
•Damaged Sidewalks
•Unhealthy Trees
•Costly Repairs
Solution: An Alternative Tree Location
Better Trees and More Shade
Now34 Feet
Recommended58 Feet
Solution: An Alternative Tree Location• Healthier Trees
• More Shade (lower home energy
cost)
• Safer Sidewalks
• Cut Repair Costs (almost to zero)
Solution: An Alternative Tree Location
Protect Street Trees: In Right-Of-Way Existing 50 feet versus Proposed 60
feet
Same Number of Lots and Larger Front Yards
Prevent Uplifted Sidewalks
• 10 Feet Separation from large trees
• Root Barriers ($100 each tree)
• Crushed Base (if located less than 10 feet from tree)
A — Status Quo
B — 50’ Right-Of-Way plus Tree Easement
C — 60’ Right-Of-Way with Trees
Options
Status Quo 50 Feet Right of Way
10’ 5’ 3’
2’ 10’Utility
EasementSide-walk
Traffic Lane
MiamiCurb
Option A
CLR/W Line 25’ Half of ROW
5’
50 Feet ROW and Tree Easement
Option B1 – Miami Curb
8’
5’Sidewalk
10’Traffic Lane
2’Curb
4’Sod10’
Utility Easement
5’Tree
Easement
CLR/W Line 25’ Half of ROW
50 Feet ROW and Tree Easement
Option B2 – Barrier Curb with 6’ Sidewalk
6’Sidewalk
10’Traffic Lane
2’ Curb
11’
5’Tree
Easement
10’Utility
Easement
CLR/W Line 25’ Half of ROW
60 Feet ROW with Tree
Option C1 – Miami Curb
5’Sidewalk
10’Traffic Lane
2’Curb
4’Sod
30’ Half of ROWCLR/W Line
10’Utility
Easement
8’
60 Feet ROW with Tree
Option C2 – Barrier Curb and 6’ Sidewalk
6’Sidewalk
10’Traffic Lane
30’ Half of ROW
2’ Curb10’
Utility Easement
11’
CLR/W Line
Sidewalks Damaged By Tree Roots
Cause: Current Requirements
Effect: Increasing Costs
Future: More Needs, Less Money
Requirements include: Land Development Code and Transportation Technical Manual (typical section)
Year 2009 $9 Million of Needs
55 miles of sidewalks require repairs
Patch
Grind
Replace
Typical Repairs
Replacement
Grinding
Comparison of Miles of Repairs Relative To Funding
0
5
10
15
20
25
30
35
FY '10 FY '11 FY '12
Mile
s of
Sid
ew
alk
$0
$1,000,000
$2,000,000
$3,000,000
$4,000,000
$5,000,000
$6,000,000
$7,000,000
Dolla
rs o
f Fu
nd
ing
Estimated Repair Total Un-repaired Backlog Estimated New Defects
6
18
2
18
7
22
2
2
18
2
$1.2 M
$0.4 M
$1.4 M
Funding
Public Works 2008 Survey Average Radius of Root Influence in Feet
Trunk Diameter
Type Tree 10 - 20 inches > 20 inches
Laurel Oak 11.3 13.0
Live Oak 7.9 17.1
Sycamore 8.9 16.0
Maple 10.4
Pine 8.4
Elm 14.7
R
• Sidewalk 10 Feet From Tree• Trees Behind Sidewalk• Roots To Be Straight
Soil required for trees by size at maturity
Height or
Spread
Soil
Area
Distance from Paved Surface
Small < 30’ 10’ x 10’ 2’
Medium < 50’ 20’ x 20’ 6’
Large > 50’ 30’ x 30’ 10’
Source: Urban Design for a Wind Resistant Urban ForestUniversity of Florida
Unsuitable Growing Area Leads to Unstable Trees
Photograph by Chuck Lippi
Tree Issues Related to Status QuoVertical and Horizontal Clearance – 10 Years
Planting
StreetStreet SidewalkSidewalk
Need 14 Feet Vertical Need 8 Feet Vertical
Tree Issues Related to Status QuoCorrections – Reduced Shade, Appearance, and
Health of Trees
10 year plantings 15 year plantings
Rate importance of each factor
3 – High2 – Medium1 – Low
Value WeightingSurvey
Environmental Numerical Value
• Tree Stability in Storms ____• Minimizing Tree Canopy Impacts ____• Minimizing Tree Root Damage ____• Tree Health ____
Costs
• Construction (New) ____• Tree Maintenance ____• Sidewalk Maintenance ____• Liability Claims ____
Livable Roadways
• Shading of Sidewalks and Streets ____• Sidewalks along Both Sides of Street ____• ADA Compliance ____• Roadway Aesthetics ____
Sustainability
• Utilities ____• Sidewalks ____• Tree Resource ____• Fiscal Responsibility ____