Streets shall conform to at least all minimum requirements of the general specifications and typical cross-sections as set forth in this Design Standards subchapter, and other conditions set forth by the Township Board and Genesee County Road Commission.
(A) Location and arrangements.
(1) The proposed subdivision shall conform to the various elements of the Master Plan and shall be considered in relation to the existing and planned major thoroughfares and secondary streets, and the part shall be platted in the location and the width indicated on the plan.
(2) The arrangement of streets shall provide for the continuation of existing streets from adjoining areas into new subdivisions, unless otherwise approved by the Township Board, following a recommendation by the Planning Commission, due to documented environmentally sensitive features, unusual lot configuration or unique site conditions. Where adjoining vacant areas are zoned or planned for development similar to the proposed subdivision, streets shall be extended to the boundary line of the tract to make provision for the future street connections. The proprietor shall demonstrate that the proposed stub street is in a reasonable location for extension into the adjacent lands, in consideration of such factors as grades, water bodies, wetlands and lot configuration.
(3) Streets shall be aligned to maximize the preservation of natural features and existing grades to the extent feasible. Streets should follow natural topography to minimize grading.
(4) The proposed subdivision street layout shall discourage use by through traffic, except where a continuation of streets to adjoining properties is deemed desirable by the township. In determining the need for these connections, the township shall consider the need for adequate access and response time for emergency vehicles, the impacts the connections may have on reducing congestion along arterials, the projected traffic volumes and the compatibility with adjacent developments.
(5) Should a proposed subdivision border on or contain an existing or proposed major thoroughfare or collector, the Planning Commission may require marginal access streets, reverse frontage with an approved screen planting contained in a non-access reservation along the rear property line having a minimum width of 15 feet, or such other treatment as may be necessary for adequate protection of residential properties and to afford separation and reduction of traffic hazards. Vehicular driveway access shall be to a minor street.
(6) Should a proposed subdivision border on or contain a railroad, expressway or other limited- access highway right-of-way, the Planning Commission may require the location of a street approximately parallel to and on each side of the right-of-way at a distance suitable for the development of an appropriate use of the intervening land as for parks in residential districts. The distances shall be determined with due consideration of the minimum distance required for approach grades to future grade separation.
(7) Half streets shall be prohibited, except where the parcel is adjacent to another platted and dedicated half street or when a contemporaneous development proposal includes the required adjacent half street. Wherever there exists, adjacent to the tract to be subdivided, a dedication or platted and recorded half street; the other half shall be platted.
(8) Where a subdivision incorporates existing public streets or private roads which are not in conformance with current standards, facilities shall be reconstructed as necessary to improve the road to the extent required by the GCRC for public roads.
(B) Specifications.
(1) Street rights-of-way roadway widths. Street and road right-of-way and roadway widths shall conform to the adopted Township Major Thoroughfare Plan and the standards adopted by the Genesee County Road Commission as evidenced by the Genesee County Master Right-of-Way Plan and the rules of the County Road Commission and the Michigan Department of Transportation. The specifications for design of various right-of-way types are provided in this section.
(2) Street gradients.
(a) Maximum grades. Street grades shall not exceed 6% (a rise or fall of 6 feet in 100 feet) on either local streets or collector streets.
(b) Minimum grades. No street grade shall be less than 0.4%.
(3) Street alignment.
(a) When street lines deflect from each other by more than 10 degrees in alignment, the centerlines shall be connected by a curve with a minimum radius of 500 feet for arterial streets, 300 feet for collector streets and 150 feet for local or minor streets. Between reverse curves, on minor streets, there shall be a minimum tangent distance of 100 feet, and on collector and arterial streets, 200 feet.
(b) The sight distance over a crest shall be a minimum of 300 feet viewed from a point 3 feet 6 inches above the surface of the pavement, with the object sighted being 3 feet 6 inches above the surface of the pavement.
(c) The minimum radii on platted street intersections shall be as follows:
1. State and federal highways, as approved by MDOT;
2. Principal county local or primary roads, 40 feet to the back of curb;
3. Residential area streets, 30 feet to the back of curb; and
4. Commercial and industrial platted streets, as approved by the Township Engineering Consultant and Fire and Police Departments.
(d) All newly platted streets which intersect with existing highways, or with proposed platted streets will do so at 90 degree angles with a minimum straightaway of 150 feet, as measured from centerline of the existing highway. The grade in the 150 foot straightaway shall not exceed 3.0%. The maximum number of intersecting streets shall be 2.
(e) Each horizontal curve on curvilinear streets shall have a minimum radius, as measured from centerline, as approved by the Township Engineer. Curves or other features principally to obtain a particular lot size, shape, appearance or scenic attraction not in keeping with good engineering design will not be permitted.
(C) Intersections.
(1) Angle of intersection. Streets shall intersect at 90 degrees or closer, thereto and in no case at less than 80 degrees.
(2) Sight triangles. Minimum clear sight distance at all street intersections and street junctions shall permit vehicles to be visible to the driver of another vehicle when each is 125 feet from the center of the intersection, and within which area no obstruction to vision, excluding existing topography, shall be permitted from a height of 2 feet to 8 feet above centerline elevation of abutting streets, except that not more than 1 tree with a trunk of not more than 30 inches in diameter, and clear of any branches for these heights may be located within the area; provided, however, that this section shall not prohibit the requirements of a greater clear vision zoning where that is necessary in view of permitted traffic turning moments, existing and anticipated traffic volumes, traffic speeds, intersection configurations, geographic and topographic conditions, or any other unique characteristics which may require a greater clear vision zone. The area of the clear vision zone shall be shown as an easement on the plat.
(3) Number of streets. No more than 2 streets shall cross at any 1 intersection.
(4) “T” intersections. Except on arterials and certain collectors, T-type intersections shall be used where practical.
(5) Centerline offsets. Slight jogs at intersections shall be avoided. Where these jogs are unavoidable, street centerlines shall be offset by a distance of 125 feet or more.
(6) Vertical alignment of intersection. A nearly flat grade with appropriate drainage slopes is desirable within intersections. This flat section shall be carried back 50 feet to 100 feet each way from the intersection. An allowance of 2% maximum intersection grade in rolling and 4% in hilly terrain will be permitted.
(D) Cul-de-sac streets. Culs-de-sac shall not be more than 1,200 feet in length. Special consideration shall be given to longer culs-de-sac under certain topographic conditions or other unusual situations. Cul-de-sacs shall terminate with an adequate turnaround with a minimum radius of 60 feet for the right-of-way.
(E) Private streets. Private streets and roads shall generally be prohibited.
(F) Half streets. Half streets generally be prohibited except where unusual circumstances make it essential to the reasonable development of a tract in conformance with these regulations and where satisfactory assurance for dedication of the remaining part of the street is provided. Whenever a tract to be subdivided borders on an existing half or partial street, the other part of the street shall be dedicated within the tract, according to the requirements of the County Road Commission.
(G) Alleys. Alleys shall generally be prohibited.
(H) Signs and signalization. The developer shall be responsible for placement of street name signs at all street intersections in accordance with the requirements of the GCRC. Where roads are proposed to be dedicated to the county, the GCRC may install the signs at the developer’s expense. The developer shall also be responsible for placement of pavement markings and regulatory street signs (such as no parking signs, stop or yield signs, speed limit signs, and warning signs) as requested by the township, the GCRC or the MDOT. All regulatory signs shall be in conformance with the Michigan Manual of Uniform Traffic Control Devices. The developer shall be responsible for placement of traffic signalization, as required by the GCRC.
(I) Phasing. Each phase of the plat shall be designed to meet the street requirements above, regardless of whether future phases are constructed.
(J) Street names. Street names shall not duplicate any existing street name in Charter Township of Clayton and Genesee County, except where a new street is a continuation of an existing street.
(1) Street names that may be spelled differently but sound the same shall be avoided.
(2) Duplications can be avoided by checking new street names with the Planning Commission’s master listing and the County Road Commission.
(Ord. 372.1 § 400, passed 6-10-1999)