Any road being constructed with the intent of becoming county maintained or petitioned as a county road shall meet the following minimum standards. See § 150.48 for drainage elements applicable to new construction.
(A) Street classification.
(1) Local street shall be any street not designed as a through street. It shall include all cul-de-sac streets and other streets designed for an anticipated traffic count of less than 1000 VPD.
(2) Collector shall be any other street.
(3) Where streets are designed to serve industrial or commercial subdivisions or sites, or developments requiring service by many heavy vehicles, the minimum design shall be that for the collector street.
(B) Pavement design.
(1) General. It is the intent of these specifications to establish a minimum allowable pavement section. All pavements shall be designed for a 20 year service life. Certification of design and design calculations shall be submitted at time of plan review. All designs shall be certified by a registered professional engineer.
(2) Minimum roadway sections.
C.A.B.
|
Bituminous (w/1" surf.) |
Concrete
|
C.A.B.
|
Bituminous (w/1" surf.) |
Concrete
| |
Local | 4" | - | 6" |
1. | |||
or | |||
2. | 8" | 4" | - |
or | 7½" | - | |
3. | - | ||
Collector | |||
1. | 6" | - | 7" |
or | |||
2. | 12" | 6" | - |
or | |||
3. | - | 10" | - |
(3) Rigid pavements.
(a) Local and cul-de-sac streets. A six-inch plain concrete pavement on four inches, compacted aggregate base on compacted subgrade. Concrete shall be Class A, structural concrete.
(b) Collector streets. A seven-inch plain concrete pavement six inches compacted aggregate base on compacted subgrade. Concrete shall be Class A, structural concrete.
(4) Flexible pavement.
(a) Local and cul-de-sac streets.
110 lbs/SY #11 Hot Asphalt Concrete (HAC) surface on 330 lbs/SY #5 Base (HAC) on 8 inches of compacted #53 base on compacted subgrade; or
110 lbs/SY #11 HAC surface on 715 lbs/SY #5 HAC base or 330 lbs/SY #5 base on 330 lbs/SY #5D base on compacted subgrade.
(b) Collector street.
110 lbs/SY #11 HAC surface on 550 lbs/SY #5 HAC base on 12 inches of compacted #53 base on compacted subgrade; or
110 lbs/SY #11 HAC surface on 220 lbs/SY #9 binder on 330 lbs/SY #5 HAC base on 330 lbs/SY #5D base or on compacted subgrade.
(5) Other acceptable pavement designs. In lieu of the minimum specifications for pavement as set out in the above, variances may be granted for other certified pavement designs, as designed by a professional engineer who is an experienced soils and testing engineer. The design shall be based upon a 20-year service life. The design shall take into account the strength of the soils on site and the anticipated present and future traffic loads on the proposed roadway. This design shall be submitted for review and approval prior to construction. The inclusion of this section is to allow for innovative approaches to design, utilizing various engineering materials and practice in order to enhance overall performance.
(C) Street layout and design standards.
(1) Minimum right-of-way. Right-of-way width shall be a minimum of 50 feet. However, areas where the roadside swales cannot be fit into the required minimum shall be extended to the toe of slope in fill areas and to the backslope on cut areas.
(2) Vertical alignment.
(a) Minimum slope: 0.5 %
(b) Maximum slope: 8.0%
(c) Vertical curve length: 100 feet (minimum), but not less than 20 feet for each percentage of algebraic difference in grade.
(d) Minimum site distance: 200 feet
(3) Horizontal alignment.
(a) Minimum radius of curve
1. Residential: 100 feet
2. Nonresidential: 200 feet
(b) Minimum length of tangent: 100 feet
(c) Minimum sight distance: 200 feet
(d) Minimum corner radius: 20 feet
(4) Cul-de-sac.
(a) Minimum R/W: 50 foot radius
(b) Minimum radius paved surface: 35 feet (measured to centerline of roadway)
(c) No obstructions or islands are to be within this area unless area is properly drained
(d) Maximum slope to be 3% in any direction.
(5) Typical cross section. Typical cross section as shown in Fig. 1 as attached to Ord. 9-1997 shall be constructed. See § 150.48 for drainage elements.
(6) Pavement widths. Pavement widths shall be based on the average VPD with an average of 7 VPD generated per lot.
Local: | less than 200 VPD | 18' |
200 VPD thru 1,000 VPD | 20' | |
Collector: | over 1,000 VPD and all other roadways | 22' |
(D) Traffic signs. New roadways shall be signed in accordance with the Manual of Uniform Traffic Control Devices for regulatory and warning signs. Street name signs shall also be required.
(BC Ord. 9-1997, passed 6-2-97)