Ashton City Zoning Code
CHAPTER 17
56 DESIGN AND CONSTRUCTION OF STREETS
17.56.010: PURPOSE:
The purpose of this chapter is to provide standards for the construction or reconstruction of streets. These standards are for streets in low to medium density residential and light commercial areas. A large scale development study (see section 17.48D.010 of this title) will be required for any development that generates sufficient traffic to necessitate additional construction requirements. (Ord. 459-13, 2013)
17.56.020: LARGE SCALE DEVELOPMENTS:
Any requirement of this chapter may be altered as a result of a large scale development study required by section 17.48D.010 of this title. (Ord. 459-13, 2013)
AS846 17.56A.txt
17.56A.010: RIGHT OF WAY WIDTH:
An eighty foot (80') right of way shall be dedicated for all streets. Where alleys are provided they shall be twenty feet (20') in width. (Ord. 459-13, 2013)
17.56A.020: GRADED WIDTH:
The paved width of streets shall be twenty five feet (25'). The rest of the right of way will be graded and graveled. (Ord. 459-13, 2013)
17.56A.030: STREET SURFACE:
Street surfaces shall be laid over a properly compacted subgrade and consist of: a) minimum twelve inches (12") of coarse aggregate subbase; b) minimum four inches (4") of crushed coarse aggregate base; and c) minimum three inches (3") of bituminous asphalt paving. This section adopts the Idaho standard of public works specifications. Truck routes will be more. (Ord. 459-13, 2013)
17.56A.040: DRAINAGE:
Street surfaces shall be crowned so as to slope away from the centerline at a grade of two percent (2%). Curbs and gutters shall be installed in the HCZD and CCZD, with appropriate provision for handling the runoff accumulated. See section 17.48.030 of this title. In other areas, shallow, parabolic drainage and snow storage areas shall be provided along all streets. These drainageways shall be reseeded promptly after construction. (Ord. 459-13, 2013)
17.56A.050: MINIMUM SIGHT DISTANCE:
Clear vision triangles shall be provided as follows:
A. At intersections: The clear vision triangle includes the area defined by extending a line between two (2) points, one on each lot line paralleling the road, each of which is thirty feet (30') from the lot corner at the intersection; and
B. At other points of access: The clear vision triangle includes the area defined by extending a line between two (2) points, one on the lot line paralleling the road, and one on the outer edge of the driveway, each of which is fifteen feet (15') from the point where the driveway crosses the lot line.
C. No fence or wall, planter, hedge, shrubbery, or other visual obstruction more than three feet (3') in height above the grade of the intersecting streets or streets and access drives shall be permitted within a clear vision triangle.
D. No parking shall be permitted in a clear vision triangle. Trees shall be permitted, but only if all branches are removed to a height of at least seven feet (7') above grade.
(Ord. 459-13, 2013)
17.56A.060: MAXIMUM GRADE:
The maximum grade of any street shall be eight percent (8%), except at intersections. The maximum grade at, and within fifty feet (50') along all approaches to, any intersection shall be two percent (2%). (Ord. 459-13, 2013)
17.56A.070: CUL-DE-SACS:
Subsection 17.48C.050B of this title requires that subdivisions extend the existing grid pattern of city streets in additions to the city and subdivisions that may reasonably be expected to be annexed. Cul-de-sacs may be used within blocks where: a) maximum cul-de-sac length shall be six hundred sixty feet (660'); and b) minimum cul-de-sac radius shall be sixty feet (60'). (Ord. 459-13, 2013)
17.56A.080: DEAD END STREETS:
Dead end streets shall be prohibited, except where temporarily permitted by a development agreement. A temporary cul-de-sac shall be provided wherever a temporary dead end street serves four (4) or more lots. (Ord. 459-13, 2013)
AS846 17.56B.txt
17.56B.010: APPROACH SPEED:
The design approach speed for all intersections shall be fifteen (15) miles per hour. This requirement may be altered as the result of a large scale development study, as provided in section 17.48D.010 of this title. (Ord. 459-13, 2013)
17.56B.020: ALIGNMENT OF INTERSECTION:
All intersections shall be at a ninety degree (90°) angle plus or minus five degrees (±5°), with both approaches running at a ninety degree (90°) angle plus or minus five degrees (±5°) for at least fifty feet (50') before the intersection. (Ord. 459-13, 2013)
17.56B.030: CURB RADIUS:
Curb radius (the radius at the intersection of the graded streets) at all intersections shall be twenty feet (20'), except at intersections with arterials, where it shall be twenty five feet (25'). (Ord. 459-13, 2013)
17.56B.040: MINIMUM CENTERLINE OFFSET OF INTERSECTIONS:
The minimum centerline offset of intersections shall be one hundred twenty five feet (125'), except for intersections with arterials, where it shall be two hundred feet (200'). (Ord. 459-13, 2013)
17.56B.050: SIGNS:
The developer shall install stop signs at all intersections with arterials. The developer shall also install all other signs required for safe traffic and pedestrian movement in the subdivision. (Ord. 459-13, 2013)
AS846 17.56C.txt
17.56C.010: CULVERTS AND BRIDGES:
All culverts and bridges shall be designed by an engineer.
A. All bridges and culverts on natural watercourses shall be designed to pass a 100-year flood without damage to the bridge or its approaches and without diverting floodwaters onto neighboring properties.
B. Culverts shall be designed to pass the runoff from the 10-year, 6-hour storm.
C. The minimum gross vehicle load supported by any bridge or culvert shall be forty thousand (40,000) pounds. A higher load bearing capacity may be required by a large scale development study, as provided in section 17.48D.010 of this title.
D. There shall be a minimum fifty foot (50'), ninety degree (90°) approach to all bridges. (Ord. 459-13, 2013)
17.56C.020: SIDEWALKS:
Sidewalks shall be installed in the HCZD and CCZD. Sidewalks shall be located within the street right of way, one foot (1') from and parallel to the outer edge of that right of way. Sidewalks shall be at least five feet (5') in width and consist of:
A. Subbase: A minimum four inches (4") of crushed coarse aggregate; and
B. Base: A minimum four inches (4") of portland cement sidewalk. (Ord. 459-13, 2013)