8.32.07 General Road Design Standards

These standards shall be applied to new developments in the Town of Daniel. (1) Roads shall be designed at a minimum in accordance with AASHTO design criteria and per street cross section drawings shown in Section 8.32.08. a. Pavement, shoulders, and sidewalks shall be designed in accordance with site specific geotechnical studies but not less than i. if the CBR of the native subgrade is less than 10 then the base shall consist of 1. nine (9) inches of granular borrow 2. nine (9) inches of ¾ inch or 1 inch road base 3. four (4) inches of asphalt ii. If the CBR of the native subgrade is greater than or equal to 10 but less than 20 1. nine (9) inches of ¾ inch or 1 inch road base 2. four (4) inches of asphalt iii. If the CBR of the native subgrade is equal to or greater than 20 1. six (6) inches of ¾ inch or 1 inch road base 2. four (4) inches of asphalt b. All materials (native and import) shall be compacted to a minimum of 95% of the maximum dry density. Dry density shall be determined using standard laboratory methods using modified effort. CBR values will be determined by the town engineer or by a licensed geotechnical engineer. (2) The roadway design standards shall be the same for all publicly owned and all privately owned roadways. (3) In road sections designated private local roadway, having ERU (Equivalent Residential Units) of 3 or less: (a) Without curb and gutter, shall be built, as shown on Figure 1 and shall meet the following criteria: (i) A four foot (4’) drainage swale; (ii) A four foot (4’) shoulder; (iii) Two (2) twelve foot (12’) recycled asphalt (rotomilled) surface lanes; and (iv) A four foot (4’) ¾ inch road base or recycled asphalt shoulder. (4) In road sections designated minor local roadways having ADT of 0-150: (a) With curb and gutter, the section shall be built, as shown on Figure 2 and shall incorporate the following criteria: (i) A four foot (4’) shoulder; (ii) A two and one half foot (2.5’) curb and gutter; (iii) Two (2) twelve foot (12’) paved surface lanes; (iv) A two and one half foot (2.5’) curb and gutter; and (v) A four foot (4’) shoulder. (b) Without curb and gutter, shall be built, as shown on Figure 3 and shall meet the following criteria: (i) A four foot (4’) drainage swale; (ii) A four foot (4’) shoulder; (iii) Two (2) twelve foot (12’) paved surface lanes; and (iv) A four foot (4’) ¾ inch road base or recycled asphalt shoulder. (5) In road sections designated Local roadways having ADT's of 151 to 1500: (a) With a curb and gutter, the sections shall be built, as shown on Figure 4 and shall meet the following criteria: (i) A four foot (4’) gravel shoulder; (ii) A two and one half foot (2.5’) curb and gutter; (iii) Two (2) twelve foot (12’) paved surface lanes; (iv) A two and one half foot (2.5’) curb and gutter; and (v) A four foot (4’) gravel shoulder. (b) Without curb and gutter, the section shall be built, as shown on Figure 5 and shall meet the following criteria: (i) A four foot (4’) drainage swale; (ii) A four foot (4’) shoulder; (iii) Two (2) twelve foot (12’) paved surface lanes; and (iv) A four foot (4’) ¾ inch road base or recycled asphalt shoulder. (c) Road sections otherwise designated local roadways in developments sharing an average frontage of less than two hundred (200) feet shall require high density road sections. (d) A development may obtain a modification of the strict requirement of a high density road section by demonstrating a substantial excess in provided parking spaces located in convenient areas designed to accommodate excess resident and visitation parking in a location separated from the actual roadway by landscaping or other non-parking areas or buildings. The burden of demonstrating that these excess parking spaces are likely to keep parking off the roadway is entirely upon the applicant and must be shown by a clear and convincing standard. (6) In road sections designated Major Local roadway, having ADT's of 1501-2000: (a) With a curb and gutter, the section shall be built, as shown on Figure 6 and shall meet the following criteria: (i) A four foot (4’) gravel shoulder; (ii) A two and one half foot (2.5’) curb and gutter; (iii) Two (2) twelve foot (12’) paved surface lanes; (iv) A two and one half foot (2.5’) curb and gutter; and (v) A four foot (4’) gravel shoulder. (b) Without curb and gutter, the section shall be built, as shown on Figure 7 and shall meet the following criteria: (i) A four foot (4’) drainage swale; (ii) A four foot (4’) gravel shoulder; (iii) Two (2) twelve foot (12’) paved surface lanes; and (iv) A four foot (4’) ¾ inch road base or recycled asphalt shoulder. (7) In road sections designated Minor Collector roadways having ADT's of 2001-8000: (a) With a curb and gutter, the section shall be built, as shown on Figure 8 and shall meet the following criteria: (i) A four foot (4’) gravel shoulder; (ii) A two and one half foot (2.5’) curb and gutter; (iii) Two (2) thirteen foot (13’) paved surface lanes; (iv) A two and one half foot (2.5’) curb and gutter; and (v) A four foot (4’) gravel shoulder. (b) Without curb and gutter, the minimum section shall be built, as shown on Figure 9 and shall meet the following criteria: (i) A four foot (4’) drainage swale; (ii) A six foot (6’) gravel shoulder; (iii) Two (2) thirteen foot (13’) paved surface lanes; and (iv) A six foot (6’) ¾ inch road base or recycled asphalt shoulder. (8) In road sections designated as High Density roadways: (a) With a curb and gutter, the section shall be built, as shown on Figure 10 and shall meet the following criteria: (i) A five foot (5’) parkway; (ii) A two and one half foot (2.5’) curb and gutter; (iii) Two (2) thirteen foot (13’) paved surface lanes; (iv) A two and one half foot (2.5’) curb and gutter; and (v) A five foot (5’) parkway. (9) In road sections designated Major Collector Roadways: (a) With a curb and gutter, the section shall be built, as shown on Figure 11 and shall meet the following criteria: (i) A five foot (5’) shoulder; (ii) A twelve foot (12’) paved surface lane; (iii) A fourteen foot (14’) median; (iv) A twelve foot (12’) paved surface lane; (v) A five foot (5’) shoulder; (vi) A two and one half foot (2.5’) curb and gutter; (vii) A five foot (5’) parkway.