Street Class
|
Right-of-Way
(feet)
|
Average Daily Traffic Volume
| |
---|---|---|---|
Major collectors
|
80
|
Above 8,000
| |
Minor collectors
|
60
|
800 - 8,000
| |
Locals
|
50
|
Less than 800
| |
Alleys (not permitted)
|
Street Class
| ||||
---|---|---|---|---|
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
|
Note: 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 conditions)
|
3
|
3
|
Street Class
|
Sight Distance
(feet)
| |
---|---|---|
Major collector
|
350
| |
Minor collector
|
275
| |
Local
|
200
|
Width
(feet)
| ||||
---|---|---|---|---|
Type of Use
|
Minimum
|
Maximum
| ||
Residential:
| ||||
Single driveway
|
8
|
20
| ||
Double driveway
|
16
|
20
| ||
Other
|
25
|
40
|
Q = CIA
| ||
Where:
| ||
Q = The required capacity, in cubic feet per
second, for the collection system at the point of design.
| ||
A = The tributary drainage area, in acres, and
shall include areas tributary from outside sources as well as from
within the site itself.
| ||
C = The coefficient of runoff applicable to
the drainage area and shall be based on consideration of soil conditions,
average slope of the drainage area and degree of ultimate development
of the area, but in no case shall be less than the following coefficients.
These runoff coefficients assume that clay soils (coefficients for
sand-gravel soils are indicated in parentheses) 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.
|
Topography
| ||||||
---|---|---|---|---|---|---|
Usage
|
Density
(units per acre)
|
Flat
(0% - 10%)
|
Rolling
(10% - 20%)
|
Hilly
(over 20%)
| ||
Residential
| ||||||
High-density
|
4-6
|
0.50 (0.40)
|
0.55 (0.45)
|
0.60 (0.55)
| ||
Medium-density
|
1-4
|
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)
|
I = The rainfall intensity, in inches per hour,
and shall be determined from the graph entitled "Rainfall Intensity
Duration for Essex and Union Counties," which is made a part hereof
and copies of which are on file with the Township Clerk.
|
Where:
| ||
R = The hydraulic radius of the conduit flowing
full.
| ||
n = Manning's roughness coefficient, which shall
be as follows. For other materials, "n" shall be as recommended by
the Township Engineer.
|
Type
|
Coefficient
| ||
Concrete pipe
|
0.012
| ||
Corrugated metal, 2 2/3" x 1/2" corrugations
| |||
Plain or fully coated
|
0.024
| ||
Paved invert
|
0.020
| ||
Fully paved
|
0.012
| ||
3" x 1" corrugation
|
0.027
| ||
6" x 2" corrugation (field-bolted)
|
0.032
|
S = The slope of the energy gradient, in feet,
per foot and shall generally be considered as being the same as the
slope of the invert of the pipe (So); however, such slopes shall be
checked against the available hydraulic gradient whenever the system
flows full or where the system discharges into a body of water.
|
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
|
Facility
|
Maximum Side Slope
| |
---|---|---|
Channel
|
2:1
| |
Ditch
|
4:1
| |
Swale
|
6:1
|