8-13D-9-23: ROADS AND CIRCULATION:

Overall Objectives: The design of the vehicular and pedestrian circulation system at Hidden Springs must meet the safety and functional intent of the Ada County Highway District (ACHDs) design standards while not compromising the aesthetic, environmental, and community building goals of the project. The circulation hierarchy and typical cross sections which follow strive to strike a balance between these two (2) requirements. The main objectives of the Hidden Springs circulation system include:

   1.   Provide a functionally efficient, safe, balanced, network of vehicular, bicycle and pedestrian facilities.

   2.   Maintain the project's rural character by using rural cross sections wherever possible.

   3.   Minimize disturbance of existing soils and vegetation.

   4.   Minimize runoff and associated erosion.

   5.   Use grassed swales wherever possible to disperse storm water, allow for maximum percolation and remove runoff pollutants.

   6.   Provide on-street parking throughout the Village Center.

   7.   Design street cross sections to a level that provides relative ease of vehicular movement, while also affording reduced speeds.

   8.   Accommodate "through" bicycle traffic on-street and "recreational" bicycle traffic both on street and on shared pedestrian/bicycle paths separated from roadways.

   9.   Allow sidewalks and shared pedestrian/bicycle paths to meander in pedestrian easements outside the road right of way for maximum design flexibility.

Notes:

(1)   Pedestrian easement may or may not be contiguous. (Typical)

(2)   The ROW shall be 80 feet for Cartwright Road southeast of its intersection with Dry Creek Road and for Dry Creek Road from its eastern terminus westward to and including the Dry Creek Bridge.

Rural Collector - Typical (Seaman's Gulch Road, Dry Creek Road, and lower Cartwright Road): Rural collectors serve to collect traffic from and distribute traffic to village streets and rural residential roadways throughout the project. They will also serve to accommodate through traffic - although through traffic will be discouraged to help maintain the rural character and minimize environmental impact to the Dry Creek Valley. The typical section includes a sixty (60') foot right of way with two (2) 12-foot travel lanes, two (2) 3-foot stabilized shoulders, and two (2) 8- foot maximum width grass swales. A single ten-foot (10') pedestrian/bicycle path will meander in a pedestrian easement generally parallel to the right of way but not always contiguous to the right of way.

Notes:

(1) Pedestrian easement may or may not be contiguous. (Typical)

Rural Collector - With Turn Lane: For rural collectors where turn lanes are needed a twelve-foot (12') center turn lane will be added as necessary to accommodate turning movement into project roadways. The section will also include travel lanes of twelve feet (12'). Otherwise, the section will remain the same as the typical rural collector.

Notes:

(1) Pedestrian easement may or may not be contiguous. (Typical)

Rural Collector - Constrained (upper Cartwright Road): The rural collector constrained section mainly occurs in the upper portion of Cartwright Road. In order to maintain the visual character and minimize the site disturbance this section has been narrowed. The typical section includes a forty-six foot (46') right of way with two (2) 12-foot travel lanes, two (2) 3-foot stabilized shoulders, and two (2) 8-foot maximum width grass swales. A single eight foot (8') shared pedestrian/bicycle path will be approximately parallel to the right of way in a separate pedestrian easement.

Notes:

(1) Pedestrian easement may or may not be contiguous. (Typical)

Dry Creek Bridge Crossing: The Dry Creek Bridge Crossing will provide enhanced capacity, safety, and the addition of separate bicycle/pedestrian facility across Dry Creek. The bridge can also serve as a primary visual identity element for the project and may become a "covered bridge" with appropriate vertical clearance and architectural style. The bridge crossing will remain in its current location. Bridge width and associated grading should be kept to a minimum to prevent impact to the riparian corridor. The typical section includes a thirty-two foot (32') wide bridge surface with two (2) 13-foot travel lanes. A single ten-foot (10') pedestrian/bicycle path will be accommodated in a separate pedestrian/bicycle bridge crossing.

Notes:

(1) Pedestrian easement may or may not be contiguous. (Typical)

Rural Residential - Typica l: Rural reside ntial streets includ e most of the roadw ays in Hidde n Spring s and will serve to carry local traffic to/from individual homesites. These roadways will be located and designed to discourage through-traffic and maintain low vehicular speeds. The typical section includes a fifty-foot (50') right of way with two (2) 11-foot travel lanes, two (2) 3-foot stabilized shoulders, and two (2) 8-foot maximum width grass swales. A single eight foot (8') shared pedestrian/bicycle path will meander beyond the ROW in a pedestrian easement as necessary.

Notes:

(1) Pedestrian easement may or may not be contiguous. (Typical)

Rural Residential - Constrained: Constrained rural residential streets occur in steeply sloped areas that cannot handle the width required for the typical rural residential section. This section includes a forty-foot (40') right of way with two (2) 11-foot travel lanes, no stabilized shoulders (but a 12-inch ribbon curb included in the 11-foot travel lane) and one grass swale on the uphill side of the street. An eight-foot (8') pedestrian/bicycle path will be located on the downhill side of the street with a wood guardrail separating it from the street for safety purposes.

Village Street - Primary (Seaman's Gulch Road, Dry Creek Road, and McFarland Road within the Village Center): Primary village streets will serve as the "main streets" of the Village Center and will accommodate the potential for commercial uses, community center, school, and village residential uses along their frontage. Village streets should establish a comfortable environment for pedestrians with slower vehicular speeds, frequent vehicular stops, on-street parking, and tree-lined sidewalks. The typical section includes a seventy-two-foot (72') ROW with two (2) 12-foot travel lanes, one ten foot (10') turn lane (where necessary) or planted median, two (2) 8-foot parallel parking lanes, and five foot (5') sidewalks set back from the curb with a five foot six inch (5'6") tree lawn on both sides of the street and within the right of way.

Village Residential (All other streets within the Village Center): Residential village streets should also establish a comfortable pedestrian environment with slow vehicular speeds, frequent vehicular stops, on-street parking, and tree-lined sidewalks. Because turning volumes for these streets should be low enough to eliminate the need for turn lanes, the typical section includes a fifty-six-foot (56') right of way with two (2) 10-foot travel lanes, two (2) 7-foot parallel parking lanes and five foot (5') sidewalks set back from the curb with a five foot six inch (5'6") tree lawn.

   Figure 3-C

(Ord. 1002, 10-28-2025)