Local Collector: Posted or proposed speed limit. Local Road: Posted or proposed speed limit, minimum 25 mph. Very Low Volume Local Road: Posted or proposed speed limit, minimum 20 mph. 2.4 Design Volumes The design volume is the traffic volume used in the design of a facility, representing the traffic expected to use the facility. Local road sub-collector, local road minor, and local road cul-de-sac shall be designed using estimated Average Daily Traffic (ADT) projections. These projections shall be for a given time period (in whole days), greater than one day but less than one year, divided by the number of days in that time period. For roadways with functional classifications of principal arterial, minor arterial, or collector, the Design Hourly Volume (DHV) concept is used. This is the 30th highest hourly volume of the future year chosen for design. For design purposes rural road or arterial DHV shall be 15 percent of ADT. For urban areas, DHV is 10 percent of the ADT. The County shall provide these design volumes to the Project Engineer upon request. For the purpose of these Standards, public roadways with an ADT of less than or equal to 400 are considered Very Low Volume Local Roads. 2.5 Design Year All roadways shall be designed to traffic volumes at the time of full build-out of the development. A reasonable yearly growth rate shall be applied to background traffic. The county engineer shall determine the growth rate used in the calculation. 2.6 Stormwater Management All roadways shall have adequate crown or cross-slope for water to run off the roadway. All stormwater management elements of the roadway within the project boundaries shall be designed in accordance with the requirements of Kitsap County Code Title 12, Stormwater Drainage. Low impact development (LID) techniques are required to the extent feasible without causing flooding or erosion impacts. See the Kitsap County Stormwater Design Manual for the applicable stormwater management and LID requirements, and the Kitsap County Green Streets Plan for additional LID guidance.
Table 3-3. Design Values for Local Roadway Features Local Roads Urban Local collector Urban (c) Local Road Urban (c) Local collector Rural Local Road Rural Lane Width (a)(b)(f) 13 ft. 11 ft. 10 ft. 8 ft. Sidewalk, both sides or Shoulder 5 ft. (e) 5 ft. (e) 4 ft. (d) ft. (d) 3 Ditch Slope (in-slope) N/A N/A 2H:1V 2H:1V For curbed, distance from face of curb to road centerline. For shouldered, distance from inside edge of shoulder to road centerline. Residential areas where on street parking is required, provide 7 additional feet. (c) Curbed section is appropriate for urban setting. (d) When guardrail is necessary, provide 2 feet of widening or longer posts to ensure lateral support. (e) When sidewalk is required as a condition of development approval. (f) Additional width may be necessary at curves 3.7.1 Cul-de-sacs Whenever a cul-de-sac dead end road extends more than 150 feet measured from the centerline of the intersecting road to the farthest extent of surfaced traveled way, a widened "bulb" shall be constructed as follows: Minimum public right of way diameter across the bulb section shall be 100 feet. The right of way diameter may be reduced, provided utilities and necessary stormwater management are accommodated on permanent easements within the development. Minimum diameter of surfacing across the bulb shall be 80 feet of paving for a curb-type road and 80 feet total for a shoulder- type road, to include 74 feet of paving and 3-foot shoulders with compacted crushed surfacing material. Public roads in areas zoned Commercial or Industrial shall have a minimum roadway diameter of 100 feet. When on-street parking is required an additional 16 feet of paving is required. Cul-de-sac Island: An optional feature for a cul-de-sac, an island, if provided, shall have a minimum diameter of 20 feet and
Table 3-4 Clear Zone Requirements Posted SPEED DESIGN ADT FILL SLOPES (H:V) CUT SLOPES (H:V) 6 : 1 or flatter 5 : 1 to 4 : 1 3 : 1 3 : 1 4 : 1 to 5 : 1 6 : 1 or flatter 40 mph Or Less Under 750 7-10 7-10 ** 7-10 7-10 7-10 750-1500 10-12 12-14 ** 10-12 10-12 10-12 1500-6000 12-14 14-16 ** 12-14 12-14 12-14 Over 6000 14-16 16-18 ** 14-16 14-16 14-16 45-50 MPH Under 750 10-12 12-14 ** 8-10 8-10 10-12 750-1500 14-16 16-20 ** 10-12 12-14 14-16 1500-6000 16-18 20-26 ** 12-14 14-16 16-18 Over 6000 20-22 24-28 ** 14-16 18-20 20-22
D. General and Construction Notes. 6.3 Time Limitation of Approval The approval of road construction plans shall be valid for a time period not to exceed 3 years from the date of approval. 6.4 Submittal Procedure Plans for proposed road construction or reconstruction shall meet the submittal requirements used for Site Development Activity Permits (SDAP). Contact the Department of Community Development for specific submittal requirements. 6.5 Changes to Approved Plans From time to time, conditions encountered during construction require modification to the design contained in the approved construction plans. Prior to making any adjustments or changes to the approved construction plans, the Project Engineer shall first receive approval from the County Engineer for such changes. Changes shall be submitted to the Department of Community Development using the SDAP procedures. Proposed modifications that the County Engineer deems substantial shall require additional review fees and re-issuance of the required permit. Minor proposed modifications may be accepted by the County Engineer without requiring the re-issuance of the accepted permit or the payment of additional review fees.