Class
|
Average Daily Traffic (ADT)
| |
---|---|---|
Expressways
|
10,001 and greater
| |
Principal Arterials
|
4,001 and 10,000
| |
Minor Arterials
|
3,001 to 4,000
| |
Major Collectors
|
2,001 to 3,000
| |
Minor Collectors
|
1,201 to 2,000
| |
Feeder Streets
|
651 to 1,200
| |
Local Streets
|
1 to 650
|
Street Classification
|
Row
(feet)
|
Cartway Width
|
Curbs
|
Sidewalks
| |
---|---|---|---|---|---|
Principal Arterial
|
120
|
*
|
*
|
*
| |
Minor Arterials
|
120
|
*
|
*
|
*
| |
Major Collector
|
100
|
40
|
*
|
*
| |
Minor Collector
|
80
|
36
|
Yes
|
Yes
| |
Feeder Streets
|
70
|
32
|
Yes
|
Yes
| |
Local Streets
|
50
|
26**
|
Yes
|
Yes
|
*
|
As recommended by PennDOT and pursuant to § 22-520, "Curbs, Sidewalks, and Trails."
| |
**
|
Parking limitations may be required by the Board of Supervisors.
|
Posted Speed
|
Center-Line Distance
| |
---|---|---|
25 MPH
|
250 feet
| |
35 MPH
|
440 feet
| |
45 MPH
|
635 feet
| |
55 MPH
|
875 feet
|
Description of Area
|
Runoff Coefficient (C)
| ||
---|---|---|---|
Residential
| |||
2 acre single-family detached lots
|
0.40
| ||
1 acre single-family detached lots
|
0.46
| ||
1/2 acre single-family detached lots
|
0.50
| ||
1/4 acre single-family detached lots
|
0.56
| ||
Two-family and multi-family
|
0.70
| ||
Commercial
|
0.75
| ||
Industrial
|
0.80
| ||
Parks and Cemeteries
|
0.38
| ||
Unimproved
|
0.35
| ||
Where the above table is not applicable, the following factors
may be used:
| |||
Roofs and all impervious surfaces
|
0.90
| ||
All other surfaces except forest
|
0.40
| ||
Forest
|
0.30
|
Storm Frequency (years)
|
Factors
| |
---|---|---|
10 and less
|
1.0
| |
25
|
1.1
| |
50
|
1.2
|
Table 22-2
| |||
---|---|---|---|
Allowable Water Velocities
| |||
Permissible velocities for channels lined with vegetation.a
| |||
The values apply to average, uniform stands of each type
of cover.
| |||
Permissible Velocity (feet per second)
| |||
Cover
|
Slope Rangeb
(Percent)
|
Erosion Resistant Soils
|
Easily Eroded Soils
|
Bermuda grass
|
0-5
|
8
|
6
|
5-10
|
7
|
5
| |
over 10
|
6
|
4
| |
Buffalo grass, Kentucky bluegrass, Smooth brome, or Blue grama
|
0-5
|
7
|
5
|
5-10
|
6
|
4
| |
Over 10
|
5
|
3
| |
Grass mixtureb
|
0-5
|
5
|
4
|
5-10
|
4
|
3
| |
Lespedeza sirecea,c Weeping love-grass,c Yellow bluestem,c Kudzu,c Alfalfa,c or Crabgrassc
|
0-5
|
3.5
|
2.5
|
Common lespedezad or Sudan grassd
|
0-5
|
3.5
|
2.5
|
a
|
Use velocities exceeding five feet per second only where good
covers and proper maintenance can be obtained
|
b
|
Do not use on slopes steeper than 10% except for side slopes
in a combination channel
|
c
|
Do not use on slopes steeper than 5% except for side slopes
in a combination channel
|
d
|
Annuals: used on mild slopes or as temporary protection until
permanent covers are established. Use on slopes steeper than 5% is
not recommended.
|
Table 22-3
| |||||
---|---|---|---|---|---|
Type M or S Inlet Capacities (In Swale)
Back Slope
| |||||
Grade
|
2:1
|
4:1
|
6:1
|
12:1
|
Dike
|
1.0
|
3.2
|
3.6
|
3.9
|
4.1
|
9.1
|
2.0
|
3.5
|
3.5
|
3.5
|
3.7
|
8.3
|
3.0
|
2.5
|
2.8
|
3.5
|
3.5
|
7.4
|
4.0
|
1.6
|
2.0
|
3.4
|
3.2
|
6.4
|
5.0
|
1.6
|
2.0
|
3.5
|
3.0
|
6.3
|
6.0
|
1.6
|
2.0
|
3.3
|
2.8
|
6.1
|
7.0
|
1.5
|
2.0
|
3.0
|
2.6
|
6.0
|
8.0
|
1.5
|
2.0
|
2.8
|
2.4
|
5.8
|
Parking
|
Aisle
| ||||
---|---|---|---|---|---|
Angle of Parking
|
Stall Width
(feet)
|
Stall Depth
(feet)
|
One-Way
(feet)
|
Two-Way
(feet)
| |
90°
|
10
|
20
|
Not Permitted
|
24
| |
60°
|
10
|
21
|
18
|
Not Permitted
| |
45°
|
10
|
20
|
15
|
Not Permitted
| |
30°
|
10
|
18
|
12
|
Not Permitted
| |
Parallel
|
8
|
22
|
12
|
18
|
Situation
|
Buffer Type
| |
---|---|---|
A new subdivision or land development regardless of abutting
land use
|
Type 1 - 30 foot width
| |
Any development adjacent to an agricultural use or district
|
Type 2 - 50 foot width
| |
Separation between residential and institutional uses or districts
|
Type 1 - 50 foot width
| |
Separation between residential and commercial or industrial
uses and districts
|
Type 1 - 50 foot width
| |
Visual screen around storage, maintenance, and waste disposal
areas
|
Type 4 - 10 foot width
| |
Reverse frontage lots where the rear yard abuts a street right-of-way
|
Type 1 - 75 foot width Landscaped berm
| |
Any use abutting required open space
|
Type 2 - 50 foot width
| |
Parking lots along roads
|
Type 3 - 10 foot width
|
Aster umbellatus- Flat Topped Aster
| |
Bidens cernua- Nodding Bur Marigold
| |
Carex comosa- Cosmos Sedge
| |
Carex lupilina- Hop Sedge
| |
Carex lurida- Shallow Sedge
| |
Carex vulpinoidea- Fox Sedge
| |
Chelone glabra- Turtlehead
| |
Elymus riparius- Riverbank Wild Rye
| |
Elymus virginicus- Virginia Wild Rye
| |
Eupatorium maculatum- Spotted Joe Pye Weed
| |
Juncus effusis- Soft Rush
| |
Mimulus ringens- Square Stemmed Monkey Flower
| |
Onoclea sensibilis- Sensitive Fern
| |
Scirpus atrovirens- Green Bulrush
| |
Scirpus polyphyllus- Many Leaved Bulrush
| |
Solidago patula- Rough Leaved Goldenrod
| |
Vernonia gigantean- Giant Ironweed
|
Trees to be Removed
|
Replacement Ratio
|
Replacement Tree Caliper
|
Replacement Rate
|
---|---|---|---|
6 - < 12" Caliper
|
40%
|
2 1/2" cal.
|
Tree for Tree
|
12 - < 24" Caliper
|
40%
|
3" cal.
|
Tree for Tree
|
24 - < 47" Caliper
|
40%
|
3" cal.
|
Inch for Inch
|
Notes:
| |
(a)
|
No tree replacement is required in the CR-1 and CM Zoning Districts.
|
(b)
|
In all districts, all trees of 48-inch caliper or greater shall
be preserved.
|
(c)
|
A combination of evergreen and flowering trees and shrubs may
be utilized to meet replacement tree requirements. Two evergreen or
flowering trees or 10 shrubs may be utilized to meet the replacement
requirement of one shade tree.
|
Acer rubrum- Red Maple
| |
Acer saccharum - Sugar Maple
| |
Celtis occidentalis - Hackberry*
| |
Carya ovata - Shagbark Hickory*
| |
Carya tomentosa - Mockernut Hickory*
| |
Fagus grandifolia - American Beech*
| |
Fraxinus americana - White Ash
| |
Fraxinus pennsylvanica - Green Ash
| |
Gleditsia triacanthos inermis - Thornless Honey Locust
| |
Gymnocladus dioicus - Kentucky Coffeetree*
| |
Liquidambar styraciflua - Sweet Gum
| |
Liriodendron tulipifera - Tulip Tree
| |
Magnolia acuminata - Cucumbertree Magnolia
| |
Nyssa sylvatica - Black Gum*
| |
Platanus acerifolia - London Plane Tree
| |
Platanus occidentalis - Sycamore
| |
Quercus alba - White Oak
| |
Quercus bicolor - Swamp White Oak
| |
Quercus coccinea - Scarlet Oak
| |
Quercus imbricaria - Shingle Oak
| |
Quercus palustris - Pin Oak
| |
Quercus phellos - Willow Oak
| |
Quercus rubra - Red Oak
| |
Quercus shumardi - Shumard Oak
| |
Tilia americana - American Linden
| |
Ulmus americana - American Elm**
|
*
|
Not to be used as street trees due to fruit, branching patterns
or other characteristics.
| |
**
|
Only disease resistant cultivars shall be permitted.
|
Amelanchier arborea - Shadbush
| |
Amelanchier canadensis - Shadblow Serviceberry
| |
Amelanchier laevis - Majestic Serviceberry
| |
Asimina triloba - Pawpaw
| |
Betula lenta - Cherry Birch
| |
Betula papyrifera - Paper Birch
| |
Carpinus caroliniana - American Hornbeam/Ironwood
| |
Cercis canadensis - Eastern Red Bud
| |
Cornus alternifolia - Alternate-Leaf Dogwood
| |
Cornus florida - Flowering Dogwood
| |
Crategus crusgalli - Cockspur Hawthorn
| |
Crataegus phaenopyrum - Washington Hawthorn
| |
Diospyros virginiana - Common Persimmon
| |
Magnolia virginiana - Sweetbay Magnolia
| |
Ostrya virginiana - American Hophornbeam
| |
Oxydendrum arboreum - Sourwood
| |
Prunus americana - American Plum
| |
Prunus serotina - Black Cherry
| |
Prunus virginiana - Shubert Chokecherry
| |
Salix nigra - Black Willow
|
Abies balsamea - Balsam Fir
| |
Ilex opaca - American Holly
| |
Juniperus virginiana- Eastern Red Cedar
| |
Picea pungens - Colorado Spruce
| |
Pinus rigida- Pitch Pine
| |
Pinus strobus - White Pine
| |
Pseudotsuga menziesii - Douglas Fir
| |
Tsuga canadensis - Canada Hemlock
| |
Tsuga caroliniana - Carolina Hemlock
|
Aesculus parvifolia - Bottlebrush Buckeye
| |
Aronia arbutifolia - Common Chokeberry
| |
Calycanthus florida - Carolina Allspice
| |
Clethra alnifolia - Summersweet
| |
Cornus racemosa - Gray Dogwood
| |
Cornus sericea - Redosier Dogwood
| |
Hamamelis vernalis - Vernal Witch Hazel
| |
Hamamelis virginiana - Common Witch Hazel
| |
Hydrangea arborescens - Smooth Hydrangea
| |
Hydrangea quercifolia - Oakleaf Hydrangea
| |
Ilex verticillata - Winterberry
| |
Itea virginica - Virginia Sweetspire
| |
Lindera benzoin - Spicebush
| |
Myrica pensylvanica - Bayberry
| |
Sambucus canadensis - American Elder
| |
Staphylea trifolia - American Bladdernut
| |
Rosa virginiana - Virginia Rose
| |
Vaccinium corymbosum - Highbush Blueberry
| |
Viburnum acerifolium - Mapleleaf Viburnum
| |
Viburnum cassinoides - Witherod Viburnum
| |
Viburnum dentatum - Arrowwood Viburnum
| |
Viburnum lentago - Nannyberry Viburnum
| |
Viburnum prunifolium - Blackhaw Viburnum
| |
Viburnum trilobum - American Cranberrybush Viburnum
|
Ilex glabra - Inkberry
| |
Juniperus communis - Common Juniper
| |
Kalmia latifolia - Mountain Laurel
| |
Leucothoe fontanesiana - Drooping Leucothoe
| |
Rhododendron maximum - Rosebay Rhododendron
| |
Taxus canadensis - Canadian Yew
| |
Thuja occidentalis - American Arborvitae
|