Q = CIA
|
Where:
| ||||
Q
|
=
|
Peak runoff rate in cubic feet per second (cfs).
| ||
C
|
=
|
Runoff coefficient equal to the ratio of the peak runoff rate
to the average rate of rainfall over a time period equal to the time
of concentration.
| ||
I
|
=
|
Average rainfall intensity in inches per hour for a time equal
to the time of concentration.
| ||
A
|
=
|
Drainage area in acres.
|
NOTE: Appropriate values for the runoff coefficient and rainfall intensity can be found in the Commonwealth of Pennsylvania Department of Transportation Design Manual, Part 2, Highway Design, Chapter 12.
|
Type of Street
|
Minimum Right-of-Way Required
|
Minimum Cartway or Paving Width
(feet)
| |
---|---|---|---|
Local
|
40
|
30
| |
Minor collector
|
50
|
36
| |
Major collector
|
80
|
36 to 48
| |
*Major arterial
|
PennDOT standard
|
*
|
Major arterial will be determined on a case-by-case basis by
City Council in accordance with PennDOT standards.
|
Minimum Pavement Thickness
| ||||
---|---|---|---|---|
Street
|
Subbase
(inches)
|
BCBC
(inches)
|
Wearing Surface
(inches)
| |
Arterial*
| ||||
Collector
|
8 of 2A modify
|
5
|
2 of bituminous surface course, ID-2*
| |
Local
|
8 of 2A modify
|
3 1/2
|
1 1/2 of bituminous surface course, ID-2*
|
*
|
Determined on a case-by-case basis.
| |
---|---|---|
NOTE: A cross section of a local street is demonstrated
in Figure 1 on the following page.[1]
|
Sidewalk Minimum Thickness
| |||
---|---|---|---|
Sidewalks
|
Subbase
(inches)
|
Surface
(inches)
| |
Concrete sidewalks
|
4 of Asshto No. 57
|
5 of Class AA concrete
|