Street Class
|
Right
of-Way
(feet)
|
Maximum
Average Daily
Traffic Volume
|
Width
(feet)
|
---|---|---|---|
Major collector
|
60
|
Above 8,000
|
40
|
Minor collector
|
60
|
800 to 8,000
|
36
|
Local
|
50
|
Less than 800
|
30
|
Alley
|
Not permitted
|
Street Class
| |||
---|---|---|---|
Design Standard
|
Major
Collector
(feet)
|
Minor
Collector
(feet)
|
Local
(feet)
|
Minimum center line radius
|
600
|
500
|
300
|
Minimum tangent between reverse curves
|
200
|
160
|
120
|
Intersection radius (curb returns)
|
40
|
30
|
25
|
Minimum intersection radius shall be determined
by the highest street class in the intersection, and the right-of-way
line shall be concentric thereto.
|
L= KA
| |
The minimum K values shall be as follows:
|
Street Class
|
Crest
Curve
|
Sag
Curve
|
---|---|---|
Major collector
|
145
|
100
|
Minor collector
|
65
|
60
|
Local
|
28
|
35
|
Intersection (stop condition)
|
3
|
3
|
Street Class
|
Sight Distances
(feet)
|
---|---|
Major collector
|
350
|
Minor collector
|
275
|
Local
|
200
|
Width
| |||
---|---|---|---|
Use
|
Minimum
(feet)
|
Maximum
(feet)
| |
Residential
| |||
Single driveway
|
8
|
20
| |
Double driveway
|
16
|
20
| |
Other uses
|
25
|
40
|
Street Class
|
Minimum Average
Maintained
Footcandles
|
Uniformity
(average to
minimum)
|
---|---|---|
Major collector
|
0.5
|
6:1
|
Minor collector
|
0.3
|
—
|
Local
|
0.2
|
—
|
Q = CIA
| |
Where:
|
Topography
| |||||
---|---|---|---|---|---|
Usage
|
Density
(units per
acre)
|
Flat
(0% to
10%)
|
Rolling
(10% to
20%)
|
Hilly
(over
20%)
| |
Residential:
| |||||
High density
|
4 to 6
|
0.50(0.40)
|
0.55(0.45)
|
0.60(0.55)
| |
Medium density
|
1 to 4
|
0.45(0.35)
|
0.50(0.40)
|
0.55(0.50)
| |
Low density
|
Less than 1
|
0.40(0.30)
|
0.45(0.35)
|
0.50(0.45)
| |
Impervious surfaces
|
—
|
0.90
|
0.90
|
0.90
| |
Undeveloped woodland
|
—
|
0.30(0.20)
|
0.35(0.25)
|
0.50(0.45)
| |
Pasture and grassed areas
|
—
|
0.30(0.20)
|
0.36(0.20)
|
0.42(0.37)
| |
Cultivated fields
|
—
|
0.50(0.50)
|
0.60(0.50)
|
0.72(0.62)
|
The above runoff coefficients assume that clay
soils (sand gravel soils coefficients indicated in parenthesis) are
present and that paved areas (parking) have been provided, and any
deviation from these factors would result in an adjustment in C values.
Determination of nonlisted uses shall be a subject of special study
and approved by the Township Engineer.
|
The minimum time of concentration shall be 10
minutes.
|
Type of Material
|
n
Value
| |
---|---|---|
Concrete pipe
|
0.012
| |
Corrugated metal, two-and-two-thirds-inches-by-one-half-inch
corrugations
| ||
Plain or fully coated
|
0.024
| |
Paved invert
|
0.020
| |
Fully paved
|
0.012
| |
Three-inches-by-one-inch corrugation
|
0.027
| |
Six-inches-by-two-inches corrugation (field
bolted)
|
0.032
|
Desirable Minimum Gradients for Concrete
Pipe
| |
---|---|
Diameter
(inches)
|
Slope
n = 0.012
|
15 (minimum permissible)
|
0.008
|
18
|
0.006
|
24
|
0.005
|
30
|
0.004
|
36
|
0.003
|
42
|
0.002
|
48
|
0.0016
|
54
|
0.0014
|
60
|
0.0012
|
66
|
0.0011
|
Unlined
|
Friction Factor
| |
Earth, uniform section
|
0.018 to 0.027
| |
Earth, nonuniform section
|
0.025 to 0.040
| |
Earth not maintained
|
0.080 to 0.012
| |
Lined
|
Friction Factor
| |
Concrete
| ||
Finished
|
0.015
| |
Rough
|
0.25
| |
Riprap
|
0.35
|
Materials
|
Velocity
(feet per second)
|
---|---|
Fine sand to fine loam
|
2.5 to 3.5
|
Stiff clay to hardpan
|
3.75 to 6.00
|
Concrete-lined ditch
|
15
|
Velocities shall be controlled by use of check
dams or baffles where necessary.
|
Facility
|
Maximum Side Slope
|
---|---|
Channel
|
2:1
|
Ditch
|
4:1
|
Swale
|
6:1
|
Street Class
|
Minimum Sight
Distance
(feet)
|
---|---|
Local
|
200
|
Minor collector
|
275
|
Major collector
|
350
|
Other
|
400
|
Area
|
Average
Maintained
Footcandles
| |
---|---|---|
Parking lots
| ||
Shopping centers
|
1.5 to 5
| |
Retail businesses
|
1.0 to 4.0
| |
Industrial
|
0.5 to 1.0
| |
Residential, multifamily
|
0.4 to 1.0
| |
Access Driveways
| ||
Shopping centers
|
2.0 to 3.0
| |
Retail businesses
|
1.0 to 3.0
| |
Industrial
|
1.0 to 3.0
| |
Park areas and pedestrianways
|
0.4
| |
Sidewalks
|
0.5
| |
Intersections
|
2.0 to 5
| |
Other areas
|
As determined by individual study
|