11.80.070 Circulation/connectivity.
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A. Circulation Plan.
1. Purpose and Applicability. The purpose of this section is to ensure adequate cross-circulation in a manner that allows subsequent developments to meet these standards, and to provide a mechanism for integrating various streets into an efficient and safe transportation network.
Developments that are required to conduct a transportation impact study or construct frontage improvements must meet the requirements of this section.
2. Information Requirements for a Circulation Plan. Applicants will submit a circulation plan that includes the subject site and all adjacent parcels. Proposed streets must be shown to the point of connection with the existing street system within 600 feet. The circulation plan will demonstrate feasibility with development of adjacent properties, or may revise the off-site portion of prior approved plans. Circulation plans must also be consistent with the Arterial Atlas, as amended. A circulation plan must be submitted at application. Draft circulation plans may be submitted at pre-application.
3. Information Requirements for Developments in Urban Area. Urban circulation plans will be schematic in nature and to an engineering scale (e.g., 1" = 100', 1" = 200', 1" = 400'). The plan should include sufficient off – and on-site conditions to evaluate it against the review criteria. The plan must include all of the following:
a. Proposed project boundary
b. Existing and proposed streets, transit routes and facilities, and pedestrian/ bicycle destinations within 600 feet of the project boundary
c. Site access points for vehicles, pedestrians, bicycles, and transit
d. Sensitive lands (wetlands, shoreline, geologic hazard, floodplain, etc.), if they are contained in the County’s information package
The circulation plan should be prepared on 8 1/2 – by 11-inch, 11 – by 17-inch, or 24 – by 36-inch format, and can be superimposed on the “arterials, C-TRAN routes, parks and trails” and “elevation contours” page provided with the developer’s GIS packet. Additional explanation or an additional legend may be required to show proposed on-site facilities adequately.
4. Review Criteria for an Urban Circulation Plan.
a. Cross-Circulation. Cross-circulation will be provided in a manner that meets these standards and, where possible, that will allow subsequent developments to meet these standards:
i. Block Length. Block lengths must be between 100 to 800 feet. Where a block is partially defined by an arterial or industrial road, the block lengths along the arterial shall be no less than the minimum full access intersection spacing specified in Table 40.350.030-3. For the purpose of this section, block length is the distance between public road intersections as measured along the nearside right of way line.
ii. Block Perimeter. The block perimeter must not exceed 3,200 feet unless accessway for pedestrian or bicycle circulation is provided or where topographic or other physical constraints preclude achieving this standard.
b. Access Street System. The access street system must:
i. Provide convenient parcel access to and from adjacent arterials and/or collectors;
ii. Be designed to discourage external traffic from shortcutting;
iii. Be designed to discourage vehicular speeds in excess of legal speed limits;
iv. Be designed for the convenient circulation of internal traffic without reliance on the arterial systems;
v. Support direct travel by pedestrians, bicyclists, and transit users; and
vi. Discourage unnecessary streets and hard surfaces.
B. Connectivity Requirements.
1. Cross Streets. On all dedicated non-arterial rights of way exceeding 800 feet in length, cross streets must be provided at intervals not greater than 800 feet in length. In order to minimize through traffic in residential neighborhoods, an overall development plan providing longer intersection intervals may be approved as long as it provides adequate vehicular circulation in the vicinity of the development. When cross street spacing exceeds 800 feet, pedestrian walkways connecting adjacent streets may be required. Cross streets must extend the full depth of the property at approximate right angles to the dedicated right of way and must provide for a minimum width of right of way and street as specified in Section 11.80.040. Cross streets must be aligned to join the existing streets at the terminal points for developing circulation of traffic and a turnaround must be constructed where required.
2. Street Extensions. Where a street has been constructed or created in such a manner as to be able to be extended or widened in accordance with this Chapter or an adopted street plan, then:
a. All residences, buildings, or structures must be constructed in such a position on the property that they will not interfere with the extension or widening of the street to other areas, and will be situated so that the extension will allow orderly and planned development for additional street installations to meet the reasonable minimum requirements of good and safe traffic circulation; and
b. Right of way or private easements necessary for such extension or widening that lie within parcels being developed will be granted or created as a condition of development approval.
3. Cross – Access Easements. Where a commercial, industrial, or multi-family residential development cannot meet the cross street requirements of this section, vehicular and pedestrian access will be provided between abutting properties to allow cross circulation and shared use of driveways. When provided, the access will consist of an easement and improvements to accomplish cross circulation. Where an abutting property has provided cross access pursuant to this section, the development will dedicate an easement and access to connect to the cross access.
C. Street Terminations and Turnarounds.
1. The length of a street termination is measured along the centerline from the intersecting street curb line to the end of street or back of turnaround.
2. With approval from the Director, a street or alley may be terminated abruptly with curbing and Type 3 barricades when the street or alley is less than 100 feet long.
3. If an attached sidewalk is allowed in cul-de-sacs where the right of way radius from the center of the cul-de-sac is less than 45 feet, thickened sidewalk (minimum 6 inch depth) with rolled curb is required.
4. The Director may restrict the length of a dead-end road or cul-de-sac where it is clearly shown that:
a. A practical alternative design results in significantly superior actual or potential road connectivity or emergency services accessibility; or
b. The presence of unstable slopes, flood risk, or other road blockage hazard presents significant potential of isolating a substantial area from emergency services.
5. The Director may require an off-street accessway or an emergency vehicle access to connect a cul-de-sac at its terminus with other streets, parks, schools, bus stops, or other pedestrian traffic generators, if the need exists for pedestrian and bike circulation.
6. Approved turnarounds may include cul-de-sacs with an approved diameter in accordance with the City’s transportation standard plans (which may include the width of the roadway), or hammerheads, intersecting public or private roads, or any alternative design approved through the road modification process. Dimensional requirements for all transportation-related features in this subsection are as shown in the City’s transportation standard plans.
7. Public Streets – Turnaround Requirements.
a. Public streets terminating in a cul-de-sac must be less than 600 feet in length. Proposed modifications to this rule will be considered by the director based on pertinent traffic planning factors such as topography, sensitive areas, and existing development.
b. A hammerhead turnaround, per T10-01B, may be approved on public streets with approval from the Director pursuant to the road modification requirements of Section 11.80.160.
c. Turnarounds will not be allowed on arterial roadways.
d. Cul-de-sacs will be constructed according to Table 11.80.070.C-1 and Table 11.80.070.C-2.
|
Maximum Length |
Radius to Right of Way |
Radius to Face of Curb |
|---|---|---|
|
200 feet |
36 feet |
30 feet |
|
400 feet |
44 feet |
35 feet |
|
600 feet |
54 feet |
45 feet |
Note 1: LID facilities may require an increased cul-de-sac radius and right of way/easement dedication
|
Maximum Length |
Radius to Right of Way |
Radius to Face of Curb |
|---|---|---|
|
600 feet |
66 feet |
60 feet |
Note 1: LID facilities may require an increased cul-de-sac radius and right of way/easement dedication
8. Private Streets (Infill and Non-Infill) – Turnaround Requirements.
a. When four or more lots are served on a private road greater than 200 feet in length, an approved turnaround must be provided at the end of the private road. Easements may be required to be expanded to accommodate turnaround requirements.
b. Rolled curb is not allowed with a reduced hammerhead.
c. Cul-de-sacs and hammerhead turnarounds will be constructed according to Table 11.80.070.C-3.
|
Length |
Number of Dwellings Served |
Radius to Right of Way |
Radius to Face of Curb |
|---|---|---|---|
|
Less than 200 feet |
Four or fewer dwellings |
No turnaround required |
|
|
Less than 200 feet |
More than four dwellings |
Reduced hammerhead per T10-01A |
|
|
200 feet to 400 feet |
N/A |
44 feet |
35 feet |
|
More than 400 feet |
N/A |
54 feet |
45 feet |
D. Pedestrian Circulation.
1. Sidewalks.
a. Applicability. Sidewalks or walkways will be constructed in accordance with the city's typical standard details and in accordance with all federal ADA standards and regulations.
b. City Sidewalks. Sidewalks will be constructed along the frontages of all streets in accordance with City transportation standard plans.
c. Downtown Sidewalks. Within the area designated as City Center, all sidewalks will be constructed to a minimum width of 12 feet.
2. Pedestrian Accessways.
a. Applicability. The review authority may require construction of an off-street pedestrian accessway at the ends of cul-de-sacs or other areas, where connections to public facilities are desirable to provide direct routes for pedestrians and bicyclists not otherwise provided by the street system to accommodate community circulation.
b. Design. Accessways will consist of a 10-foot minimum public easement and may be entirely hardscaped. All surfaces will be designed to drain stormwater run-off to the side or sides of the accessway unless constructed as an LID facility. Accessways must comply with ADA standards.
c. Visibility. Accessways will be constructed so that the entirety of the accessway is visible from one or more adjacent public streets. On-street parking will be prohibited within 15 feet of the intersection of an accessway and a public street to preserve safe sight distances. A vertical clearance of 8 feet is required.
d. No Vehicular Access. Accessways will be designed to prohibit motorized traffic. Curbs, bollards, or branching the accessway into two narrower one-way paths before it reaches the roadway are suggested design considerations.
e. Stairways. Stairways may only be provided in addition to the accessway. Stairways will be at least 5 feet wide, with a center handrail and flat, sloped surfaces will be provided along the outside to walk bicycles.
3. Sidewalk Construction Timing. Sidewalks will be installed in conjunction with either the construction of an adjacent street or the construction of a building prior to issuance of a certificate of occupancy.
4. Construction Bond. If the director determines that construction is not feasible when a building is ready for occupancy, a construction bond or other security acceptable to the Director must be posted guaranteeing the construction of required sidewalks. The amount of such construction bond, or other security, will be set by the Director based upon the estimated cost of installation at the time when the sidewalk is to be constructed.
E. Bicycle Circulation. Applicability. Bicycle lanes will be provided in the reconstruction or new construction of any arterial or collector street in accordance with the Comprehensive Plan and Arterial Street System and Classification Map.
F. Bicycle Parking. Applicability. Bicycle parking is encouraged and, when provided, shall meet the requirements of Chapter 11.60 and Chapter 20.945. (Ord. M-4176 §13, 2016; Ord. M-4026 §10, 2012)