Type of Street
|
Right-of-Way
(feet)
|
Pavement*
(feet)
|
---|---|---|
Arterial**
|
Variable
|
Variable
|
Collector
|
70
|
24
|
Local residential (minor)
|
60
|
20
|
Cluster
|
50
|
20
|
Marginal service (access)
|
40
|
20
|
NOTES:
| ||
*Pavement width does not include the width
of curbs or gutters.
| ||
**Design generally controlled by state or county
highway criteria.
|
Geometric Standards for Streets
| ||||
---|---|---|---|---|
Standard
|
Arterial2
|
Collector4
|
Minor and Marginal Access
|
Cluster
|
Maximum grade1
|
4%
|
6%
|
7%
|
8%
|
Minimum grade
|
0.5%
|
0.5%
|
0.5%
|
0.5%
|
Minimum vertical sight distance3
|
600 feet
|
300 feet
|
200 feet
|
150 feet
|
Minimum center line radius for horizontal curves
|
500 feet
|
300 feet
|
150 feet
|
100 feet
|
Minimum length of vertical curves
|
200 feet; in no case less than 30 feet for each
|
100 feet; in no case less than 20 feet for each
|
Same as minor street
| |
Minimum length of tangents between curves
|
200 feet
|
1-percent difference of grade 100 feet
|
1-percent difference of grade 100 feet
| |
NOTES:
1 Steeper grades
may be allowed upon written approval from the Planning Board.
| ||||
2 Design generally
controlled by state or county highway criteria.
| ||||
3 Sight distance
shall be measured between two (2) points along the center line of
the street on a straight line entirely within the street right-of-way
and clear of obstructions, one (1) of the points to be at the surface
of the street and the other four and one-half (41/2) feet above the
surface.
| ||||
4 Collector streets
which do not service an area containing at least one hundred fifty
(150) dwelling units under ultimate area development may be considered
as minor streets for purposes of design standards. The service area
of a collector includes those dwelling units on minor streets which
feed into the collector.
|