40.350.030 Street and Road Standards

A.    Overview.

1.    Purpose. It is the purpose of this section to establish minimum standards for public and private transportation facilities for vehicles, public transit, pedestrians, and bicycles, hereinafter constructed or improved as a condition of county approval of a development, or a transportation project constructed by the county. These standards are intended to preserve the community’s quality of life and to minimize total costs over the life of the transportation facility.

2.    Applicability. This section applies to any subdivision, short plat, site plan application, or conditional use permit; provided, that for the purposes of Sections 40.350.030(B)(4) and (B)(8), it shall also apply to applications for building permit or other applications for access to a public road, or to projects within the public right-of-way. Unoccupied utility and wireless communication facilities shall only be subject to the provisions of Section 40.350.030(B)(4)(c), (d) and (e); and Section 40.350.030(B)(8). Private bridges are addressed in Section 40.350.040.

3.    Relationship to Comprehensive Plan.

a.    Clark County is required by RCW 36.70A.040(3) to ensure that any development regulations adopted subsequent to the comprehensive plan “...are consistent with and implement the comprehensive plan...”

b.    This section is consistent with and implements the goals and policies listed in the comprehensive plan. Particular attention has been paid to Chapter 5, Transportation Element.

c.    Interpretations of this section shall be consistent with the effective Arterial Atlas. The Arterial Atlas identifies all arterials and collectors and specifies the design of these facilities in general terms.

d.    This section implements the pedestrian and bikeways system plan and the Arterial Atlas. The atlas requires pedestrian and/or bicycle facilities to be included as part of certain arterial and collector road cross-sections where the pedestrian and bikeways system plan indicates such facilities are to be located. This section requires the inclusion of pedestrian and bikeway facilities in frontage improvements based on the functional classification adopted in the Arterial Atlas.

4.    Functional Classifications – Purpose. The purpose of a functional classification system for county roads is to define varying levels and types of transportation facilities that provide for the safe and efficient movement of people and goods, while preserving residential areas and maintaining the economic vitality of commercial and industrial areas. The system classifies transportation facilities as either urban or rural roads. Both urban and rural roads are further divided into arterials, collectors, and access roads. There is also an urban commercial/industrial category of roads.

    Existing and proposed arterials and collectors are shown on the current Arterial Atlas. The county’s functional classification system for arterials is intended to be in compliance with the federal classification system.

5.    Functional Classifications – Urban Roads. Urban roads are classified as outlined below:

a.    Arterials.

(1)    Parkway Arterial. “Parkway arterial” is the highest classification within the county’s functional classification system. The purpose of this county road is to carry high volumes of traffic through the urban area and between major regional activity centers. This class of roadway is of primary importance in the regional transportation system as it carries a high proportion of the total urban-area travel. Access is normally limited to intersections with other arterials. Direct land access is prohibited.

(2)    Principal Arterial. “Principal arterial” is the basic element of the county’s road system. All other functional classifications supplement the principal arterial network. It carries large volumes of traffic over long distances. Access is generally limited to intersections with other arterials and collectors. Signalized intersection spacing is regulated. Direct land access is minimal and managed, but is less restrictive than access from parkway arterials. Spacing is typically two (2) to five (5) miles.

(3)    Minor Arterial. “Minor arterial” collects and distributes traffic from principal arterials to streets of lower classifications and may allow for traffic to directly access destinations. Minor arterials provide for movement within subareas of the county, whose boundaries are largely defined by principal arterial roadways. They serve through traffic and provide direct access to large commercial, industrial, office and multifamily development but, generally, not to single-family residential properties. Spacing is typically less than two (2) miles.

b.    Collectors – Urban Collector. “Urban collector” provides for land access and traffic circulation within and between residential neighborhoods, and commercial and industrial areas. The collector street also collects traffic from local streets and channels it into the arterial system. Direct access to adjacent land uses, however, is still subordinate to traffic movement. Access to abutting properties is controlled through driveway spacing and pavement markings. Typically, collectors are not continuous for any great length, nor do they form a connected network by themselves. Spacing is typically less than two (2) miles.

c.    Access Roads.

(1)    Neighborhood Circulator. “Neighborhood circulator” serves to distribute traffic from collectors and provides direct access for abutting properties. Through trips are discouraged and parking is allowed. In general, these streets connect local access streets to collectors.

(2)    Local Access. “Local access” streets provide direct access to adjoining properties within a neighborhood. Through trips are discouraged and parking is usually allowed. In general, these streets do not directly connect to arterials or collectors.

(3)    Short Cul-de-Sac. “Short cul-de-sac” streets are a maximum one hundred fifty (150) feet in length and serve no more than eighteen (18) dwelling units. Parking is allowed. The use of shared driveways off of short cul-de-sacs requires fire marshal approval.

(4)    Alley. “Alley” streets are secondary accesses to the back side of lots. This allows streets at the front of properties not to be encumbered with driveways. Alleys are an alternative to frontage access. Parking is not allowed.

d.    Urban Commercial/Industrial. “Urban commercial/industrial” streets serve to distribute traffic from arterials and provide direct access to abutting commercial or industrial properties. Through trips are discouraged and parking is optional. Bike lanes may be required when the projected averaged daily trips exceed three thousand (3,000).

    A “storefront street” is a pedestrian-oriented street type that can be used in Mixed Use and Highway 99 commercial districts where building setbacks are zero (0) to five (5) feet. Driveway access is not permitted; wide sidewalks, curb bulb-outs and parking are required.

6.    Functional Classifications – Rural Roads. Rural roads are classified as follows:

a.    Rural Arterial. “Rural arterial” roads are rural extensions of urban principal arterials and some urban minor arterials. They provide adequate right-of-way for future urban arterial routes. The provision of land access remains subordinate to providing for traffic movement. Parking is not allowed.

b.    Collectors.

(1)    Rural Major Collector. “Rural major collector” roads are rural extensions of urban minor arterials and some urban collectors. Their primary purpose is to link rural centers with nearby towns and cities and with state arterial routes. The provision of land access remains subordinate to providing for traffic movement. Parking is not allowed.

(2)    Rural Minor Collector. “Rural minor collector” roads connect local traffic to rural major collectors and state arterial routes and may be rural extensions of urban minor arterials or urban collectors. They are spaced so as to be accessible to all developed areas within the county. The provision of land access is given the same priority as the provision of traffic movement. Parking is not allowed.

c.    Access Roads.

(1)    Local Access. “Local access” roads provide access from parcels to the rural collector system. Parking is not allowed.

7.    Scenic Routes.

a.    Scenic routes are roadways with unique scenic or historical features, officially designated by the Board of County Commissioners. Scenic routes seek to enhance, preserve and facilitate the enjoyment of those scenic or historical features unique to each route.

b.    Scenic route design may allow reduced design speed and modified roadway and right-of-way widths to preserve naturally occurring scenic beauty unique to the location of the route. When possible, existing alignment and roadway sections shall be used. Special features, such as vehicle turnouts for vista areas or bicycle/pedestrian facilities, may be provided. Urban or rural collector standards shall be used for right-of-way and roadway sections. The Public Works Director may modify the standards to accommodate unique scenic or historic design considerations.

c.    A traffic analysis to determine the impacts on arterials, collectors, and access roads shall be completed prior to designating a facility a scenic route.

8.    Urban Reserve, Urban Holding Areas and Rural Centers. The following are special applications of the functional classifications. Chapter 5 of the comprehensive plan lists additional transportation improvements required in specific geographic areas.

a.    New developments permitted outright within the urban holding and urban reserve areas of the county shall meet rural road standards, except that the right-of-way for rural local access roads shall be a minimum of fifty-four (54) feet to allow for a future neighborhood circulator street.

b.    Compliance with the urban road standards for right-of-way dedication and frontage improvements shall be required for:

(1)    Conditional uses in urban holding areas; and

(2)    Conditional uses that are urban in character, within urban reserve areas.

c.    Where urban frontage improvements are required and the road to be improved has a rural classification, Table 40.350.030-1 shall be used to convert rural classifications to urban.

d.    New developments within rural centers shall meet rural road standards. All public and private roads shall be paved and constructed with sidewalks.

Table 40.350.030-1. Rural/Urban Classification Conversion

Rural Classification

Converts to

Urban Classification

Rural Arterial (RA)

← →

Principal or Minor Arterial

Rural Major Collector (R-2)

← →

Minor Arterial or Collector: two lanes, center turn lane and bike lanes (M-2cb or C-2cb)

Rural Minor Collector (RM-2)

← →

Collector: two lanes (C-2)

Rural Local Access

← →

Neighborhood Circulator

(Amended: Ord. 2006-09-13; Ord. 2007-09-13; Ord. 2007-11-13; Ord. 2008-06-02; Ord. 2009-06-01; Ord. 2009-12-01; Ord. 2012-05-14; Ord. 2012-05-30)

B.    Standards for Development Review.

1.    Transportation Impact Study. The requirements for a transportation impact study are stated in Section 40.350.020(D).

2.    Circulation Plan.

a.    Purpose and Applicability. The purpose of this section is to ensure adequate cross-circulation in a manner which 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 shall meet the requirements of this section.

b.    Information Requirements for a Circulation Plan. Applicants shall submit a circulation plan which includes the subject site and all adjacent parcels. Proposed streets must be shown to the point of connection with the existing street system within six hundred (600) feet. The circulation plan shall demonstrate feasibility with development of adjacent properties, or may revise the off-site portion of prior approved plans. Circulation plans shall also be consistent with the Arterial Atlas, as amended. A circulation plan shall be submitted at application. Draft circulation plans may be submitted at pre-application.

(1)    Information Requirements for Developments in Urban Area. Urban circulation plans shall be schematic in nature and to an engineering scale (e.g., 1" = 100', 1" = 200', 1" = 400'). The plan should include sufficient off-site and on-site conditions to evaluate it against the review criteria. It shall include:

(a)    Proposed project boundary;

(b)    Existing and proposed streets, transit routes and facilities, and other pedestrian/bicycle destinations within six hundred (600) feet of the project boundary;

(c)    Site access points for vehicles, pedestrians, bicycles, and transit; and

(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 eight and one-half (8 1/2) inch by eleven (11) inch (8 1/2" x 11") or eleven (11) inch by seventeen (17) inch (11" x 17") or twenty-four (24) inch by thirty-six (36) inch (24" x 36") 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 adequately show proposed on-site facilities.

(2)    Information Requirements for Developments in Rural Area. Rural circulation plans shall be schematic in nature and based on the appropriate quarter-section map. The plan should include sufficient on-site and off-site conditions to evaluate it against the review criteria. Rural circulation plans shall include:

(a)    Proposed project boundary;

(b)    How the project site connects to the existing street system;

(c)    Any arterials identified in the Arterial Atlas, as amended, within eight hundred (800) feet of the site.

c.    Review Criteria for an Urban Circulation Plan.

(1)    Cross-Circulation. Cross-circulation shall be provided in a manner that meets these standards and, where possible, that will allow subsequent developments to meet these standards:

(a)    Block Length. Block lengths shall be between one hundred (100) to eight hundred (800) feet; provided, that 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.

(b)    Block Perimeter. The block perimeter shall not exceed three thousand two hundred (3,200) feet unless accessway(s) for pedestrian or bicycle circulation are provided or where topographic or other physical constraints preclude achieving this standard.

(2)    Access Street System. The access street system shall:

(a)    Provide convenient parcel access to and from adjacent arterials and/or collectors;

(b)    Be designed to discourage external traffic from short-cutting;

(c)    Be designed to discourage vehicular speeds in excess of legal speed limits;

(d)    Be designed for convenient circulation of internal traffic without reliance on the arterial systems;

(e)    Support direct travel by pedestrians, bicyclists, and transit users; and

(f)    Discourage unnecessary streets and hard surfaces.

3.    Transportation Design Criteria. The design criteria set out in Tables 40.350.030-2 and 40.350.030-3 are adopted as a portion of the Clark County standard specifications. Such criteria are applicable to roads located within and adjacent to a development. These criteria are intended for normal conditions. The responsible official may require higher standards for unusual site conditions.

    All urban roads except alleys consist of a core road section and a flex zone section.

a.    The core road consists of the traveled way portion of the road, as well as medians and turning lanes on higher classification roads. Core road features as shown on the Standard Detail Drawings allow little, if any, variation unless a road modification request is approved.

(1)    Travel and turning lanes require impervious pavement on all rural roads, and urban arterials, collectors, industrial/commercial, and neighborhood circulator roads.

(2)    Permanent median areas may utilize stormwater low impact development features including, but not limited to, bioretention swales and permeable pavement. Such features shall be subject to approval by the Public Works Director and shall be designed to ensure adequate public safety.

b.    The flex zone consists of that portion of the roadway outside of the core road. Flex zone features can include stormwater best management practice features, parking and bike lanes, sidewalks, and planter and utility strips, depending on the road classification. These features may be designed with considerable flexibility subject to engineering approval by the county; however, all features applicable to the road classification shall be provided. Some flex zone features may require more right-of-way than is noted in Table 40.350.030-2.

(1)    Stormwater Features. Stormwater low impact development features as found in the Clark County Stormwater Manual are allowed with approval from the Public Works Director. Stormwater features shall be designed and constructed to ensure adequate public safety. Right-of-way in excess of that required in Table 40.350.030-2 may be needed to accommodate stormwater features.

(a)    Permeable Pavement. Permeable pavement may be used for the following:

(i)    Sidewalks and separated bike lanes on all road classifications;

(ii)    Parking and nonseparated bike lanes of all urban access roads, including neighborhood circulators; and

(iii)    Travel lanes of all urban access roads except neighborhood circulators.

(iv)    Prior to acceptance of permeable pavement surfaces by the county, the applicant shall sign a Permeable Pavement Testing and Acceptance Agreement in a form acceptable by the Public Works Director.

(b)    Infiltration Systems. Infiltration systems such as bioretention systems, rain gardens and infiltration planters are subject to the following limitations:

(i)    Infiltration from stormwater features shall not threaten the safety or integrity of underground utilities. The Public Works Director shall require that infiltration features located in close proximity to utilities be designed to accommodate the utilities;

(ii)    Infiltration from stormwater features shall not adversely affect the function and integrity of the core road.

(2)    On-Street Parking. Where required, on-street parking shall be subject to the following:

(a)    Angled “head-in” parking may be allowed with approval of the Public Works Director; provided, that backing over sidewalks or bicycle lanes is prohibited;

(b)    Curb extensions containing bioretention facilities are allowed in parking lanes subject to the following:

(i)    Curb extensions shall not extend more than seven (7) feet into the parking lane, and shall not interrupt required bike lanes.

(ii)    On commercial/industrial roads, the length of mid-block curb extensions is limited to twenty percent (20%) of the curb length of a block, or in the case of a partial block development, the road frontage of the site.

(iii)    Mid-block curb extensions are prohibited on arterials, collectors and storefront roads.

(iv)    Mid-block curb extensions on all urban access roads, including neighborhood circulators, are allowed with restrictions in residential subdivisions under one (1) of the following options:

[a]    Curb extensions can occupy up to ten percent (10%) of the curb length of a block, or in the case of a partial block development, the road frontage of the site;

[b]    Curb extensions can occupy up to twenty-five percent (25%) of the curb length of a block, or in the case of a partial block development, the road frontage of the site; provided, that the applicant demonstrate on the plat that fifty (50) foot long two (2) way passing opportunities are provided at one hundred fifty (150) foot maximum intervals along the roadway for urban local access roads. Acceptable methods include the use of abutting driveways, twenty (20) foot wide travel way clear zones, or other methods as may be approved by the Public Works Director; or

[c]    Curb extensions can occupy more than twenty-five percent (25%) of the block length; provided, that the applicant demonstrate on the plat that at least one (1) on-street parking space per lot is maintained. Single on-street parallel parking spaces between driveways shall be at least seventeen (17) feet in length, measured from five (5) feet from the top of the slope of the driveway wing or end of the curb radius. Two (2) or more consecutive on-street parallel parking spaces shall require two (2) additional feet between each space.

(v)    Curb extensions up to fifty (50) feet long are allowed at intersections of local access roads and short cul-de-sacs, or combinations thereof. Curb extensions at intersections may be required for storefront streets, subject to Section 9.1.2 of the Highway 99 Overlay District Standards in Appendix F to Title 40, or for mixed use developments. Such extensions shall not count toward the mid-block percentage requirements in this subsection. Approval of such curb extensions shall require demonstration of adequate vehicular turning movement capability.

(vi)    Measurements. The length of mid-block curb extensions shall be measured between the tangents of the standard curb. The length of curb extensions at intersections shall be measured between the tangent of the standard curb and the face of the curb of the intersecting street. “Block length” is the distance between road intersections as measured along the nearside right-of-way or easement line.

(3)    Bike Lanes. Bike lanes, when required by the road classification, are subject to the following:

(a)    Bike lanes may abut travel lanes or be located outside of the curb line, depending on the feasibility of existing and future connections.

(b)    When combined with pedestrian paths, the combined width shall be a minimum of ten (10) feet wide.

(c)    Bike lanes shall be continuous through a development, i.e., cannot be interrupted by curb extensions or other features.

(4)    Sidewalks. Sidewalks shall be provided on both sides of all public streets in urban areas and within rural centers, subject to the following:

(a)    Attached and detached sidewalk widths shall be as noted in Table 40.350.030-2.

(b)    When combined with bike lanes, the combined width shall be at least ten (10) feet.

(c)    Sidewalks shall be continuous through a development, i.e., cannot be interrupted by curb extensions or other features.

(d)    Other than for sidewalks in rural center zones where the standard right-of-way dedication is insufficient, sidewalks may be allowed within easements only where it is demonstrated that such sidewalks cannot be located within the established public right-of-way or private roadway tract due to natural features (e.g., significant trees, rock outcroppings, steep topography, etc.) that should be preserved, or irregular lot configuration.

(5)    Utilities. For new developments, the Public Works Director shall require that underground utilities be designed to accommodate infiltration features that are in close proximity to the utilities.

(6)    Curb and gutter, when required, shall be a minimum of eighteen (18) inches wide. When curbs are required, vertical curb is required for all roads except for cul-de-sac bulbs.

Table 40.350.030-2 

Roadway Type

Applicable
Zoning

Standard Detail #

Right-of-Way

Roadway Width

# Travel Lanes/ Surface1

Lane Width

CTL/ Median/ Surface1,2

Bike Lane or Paved Shoulder (2 Sides)/ Surface

Sidewalk/ Surface

Parking/ Surface1

Total Planter/ LID/Utility

Urban Classifications

Arterial

Parkway (Pa-4b)

All

1

120'

74' – 80'

4/IMP

12'

10' – 16'

8' shoulders3/IMP

12' trail/P

None

28 – 34'

Principal (Pr-4cb)

All

2

100'

72'

4/IMP

11' & 12'

14'

6' bike lanes

6'4/P

None

16'

Minor (M-4cb)

All

3

100'

72'

4/IMP

11' & 12'

14'

6' bike lanes

6'4/P

None

16'

Minor (M-2cb)

All

4

72'

48'

2/IMP

12'

12'

6' bike lanes

6'4/P

None

12'

Collector

Urban (C-2cb)

All

5

70'

46'

2/IMP

11'

12'

6' bike lanes

6'4/P

None

12'

Urban (C-2)

All

6

60'

38'

2/IMP

11'

None

None

6'4/P

8' both sides

10'

Urban (C-2b)

All

7

60'

34'

2/IMP

11'

None

6' bike lanes

6'4/P

None

14'

Commercial/Industrial

Local

All commercial & industrial zones

8

60'

42'

2/IMP

14'

14'

None

6'4/P

None

5'

Local w/ Bike Lanes

All commercial & industrial zones

9

70'

52'

2/IMP

14'

14'

5' bike lanes

6'4/P

None

5'

Local w/ Parking

All commercial & industrial zones

10

60'

38'

2/IMP

14'

None

None

6'4/P

10' one side

9'

Storefront

Mixed use & Hwy 99 overlay

11

65'

40'

2/IMP

12'

None

None

8'/P

8' both sides

4' tree wells both sides

Access

Neighborhood Circulator

All urban residential zones

12

54'

36'

2/IMP

10'

None

None

5'/P

8' both sides

7'

Urban Local

All urban residential zones

13

46'

28'

1/P

12'

None

None

5'/P

8' both sides

7'

Short Cul-de-sac

All urban residential zones

14

44'5

26'5

1/P

10'

None

None

5'/P

8' both sides

7'

Private Road

All urban zones

15

26' easement

20'

2/P

10'

None

None

5' one side/P

None

0'

Private Road

All urban zones

16

30' easement

24'

1/P

16'

None

None

5' one side/P

8' one side

0'

Alley

All urban zones

17

26'

20'6

1/P

16'

None

2' shoulders

None

None

6'

Rural Classifications

Arterial

Rural Arterial (RA)

All rural & resource zones

18

100'

40'

2/IMP

12'

None

8' shoulders

None

None

60'

Collector

Major (R-2)

All rural & resource zones

19

60'7

40'

2/IMP

12'

None

8' shoulders

None8

None

20'

Minor (Rm-2)

All rural & resource zones

20

60'7

40'

2/IMP

12'

None

8' shoulders

None8

None

20'

Access

Rural Local

All rural & resource zones

21

50'9,10

24'

2/IMP

10'

None

2' shoulders

None11

None

26'

Private Road

All rural & resource zones

22

30'9 (Easement)

20'

2/P

10'

None

None

None11

None

10'

1 IMP = Impervious pavement; P = Permeable pavement. Permeable pavement, when noted, is allowed, but not required. See Section 40.350.030(B)(3)(b)(1)(a) for additional details regarding bike and parking lane surfacing requirements.

2 Permanent medians fourteen (14) feet wide or greater may be raised or include stormwater LID features subject to Section 40.350.030(B)(3)(a)(2). Twelve (12) foot wide medians may include turn lanes. Turn lanes shall be impervious pavement.

3 Shoulders may be widened for short distances where guardrail is planned. Parking limited to urban collectors (two (2) lanes).

4 Sidewalk width may be reduced to five (5) feet if detached.

5 Short cul-de-sac minimum R/W is thirty-five (35) foot radius with a constructed thirty (30) foot radius.

6 Twenty (20) foot unobstructed width.

7 In rural centers additional R/W or public easements for sidewalks may be required.

8 In rural centers, sidewalks and eighteen (18) inch curb and gutter required. Detached sidewalks shall be at least five (5) feet wide; attached sidewalks shall be at least eight (8) feet wide.

9 In rural centers, additional R/W or public easements for walkways or ditches may be required.

10 Within the “urban reserve” areas of the county, the right-of-way shall be fifty-four (54) feet.

11 In rural centers, detached, at-grade paved (concrete or asphalt) walkways, at least five (5) feet wide, are required. Public streets shall require walkways on both sides of the street. Private streets shall require walkways on at least one (1) side.

(Amended: Ord. 2012-05-14; Ord. 2014-01-08)

Table 40.350.030-3 

Roadway Type

Design Speed (MPH)

Maximum Grade (%) Flat1

Maximum Grade (%) Rolling1

Maximum Grade (%) Mountainous1

Minimum Centerline Radius (ft.) Flat

Minimum Centerline Radius (ft.) Rolling

Minimum Centerline Radius (ft.) Mountainous

Design Volume (ADT)

Minimum Full Access Intersection Spacing (ft.)

Minimum Full Access Intersection Curb Return Radii (ft.)2,3

Minimum R/W Radius Chords

Urban Classifications

Arterial

Parkway (Pa-4b)

50

6

7

9

1,145

715

410

24,000

1,000

35

25

Principal (Pr-4cb)

50

6

7

9

1,145

715

410

24,000

600

35

25

Minor (M-4cb)

40

6

8

10

955

560

410

18,000

500

35

25

Minor (M-2cb)

40

6

8

10

955

560

410

16,000

500

357

25

Collector

Urban (C-2cb)

35

7

9

10

575

440

330

16,000

275

357

25

Urban (C-2)

35

7

9

10

575

440

330

12,000

275

357

25

Urban (C-2b)

35

7

9

10

575

440

330

12,000

275

357

25

Commercial/Industrial

Local

40

7

9

10

575

440

300

12,000 – 24,000

275

50

40

Local w/ Bike Lanes

35

7

9

10

575

440

300

12,000 – 24,000

275

45

35

Local w/ Parking

35

7

9

10

575

440

300

12,000

275

45

35

Storefront

25

7

9

10

200

200

200

12,000

275

354

354

Access

Neighborhood Circulator

25

15

15

15

150

150

150

3,000

150

25

NA

Urban Local

25

15

15

15

704

704

704

1,500

100

25

NA

Short Cul-de-sac

25

18

18

18

704

704

704

180

100

20

NA

Private Road

25

18

18

18

704

704

704

1,000

100

See Dwg F16 or F17

NA

Private Road

25

18

18

18

704

704

704

1,000

100

See Dwg F16 or F17

NA

Alley

NA

18

18

18

NA

NA

NA

NA

100

See Dwg F16 or F17

NA

Rural Classifications

Arterial

Rural Arterial (RA)

50 flat

40 rolling

30 mountainous

6

8

10

955

560

410

10,000+

500

35

25

Collector

Major (R-2)

50 flat

40 rolling

30 mountainous

6

8

10

955

560

410

10,000

500

35

25

Minor (Rm-2)

50 flat

40 rolling

30 mountainous

6

8

10

575

440

300

5,000

275

35

25

Access

Rural Local

30

15

15

15

150

150

150

2,000

150f

25

NA

Private Road

256

18

18

18

60

60

60

500

100f

25

NA

1 May be steeper for short distances where permitted by AASHTO Guidelines.

2 Intersection of two (2) different street classifications shall use the larger intersection radius.

3 Must meet state standards if intersecting state roads.

4 Storefront streets may require curb extensions at intersections subject to Section 9.1.2 of the Highway 99 Overlay Standards, or for Mixed Use developments.

5 Except for where the curve is between eighty (80) to one hundred ten (110) degrees, a minimum thirty-five (35) foot radius may be used.

6 Design speed for rural private road may be reduced to twenty (20) miles per hour without road modification, if topography imposes severe restriction and has approval from the County Engineer.

7 Forty-five (45) foot radius will be required on roads where truck/transit will use, and there is only one (1) lane of traffic.

(Added: Ord. 2012-05-14)

4.    Access Management.

a.    Applicability. As noted in Section 40.350.030(A)(2), this subsection also applies to applications for building permits and applications for access to public roads.

b.    Access to Local Access Roads.

(1)    Driveway Spacing.

(a)    Excepting the bulbs of cul-de-sacs, driveways providing access onto nonarterial streets serving single-family or duplex residential structures shall be located a minimum of five (5) feet from the property lines furthest from the intersection. Where two (2) driveways are permitted, a minimum separation of fifty (50) feet shall be required between the driveways, measured from near edge to near edge.

(b)    Corner lot driveways shall be a minimum of fifty (50) feet from the intersecting property lines, as measured to the nearest edge of the driveway, or in the case where this is impractical, the driveway may be limited to twenty (20) feet in width and located five (5) feet from the property line away from the intersection or as a joint use driveway at this property line. Where a residential corner lot is located at the intersection of a nonarterial street with an arterial street, the corner clearance requirements of Section 40.350.030(B)(4)(c)(2)(f) shall apply to the nonarterial street.

(c)    Flag lots and joint driveways serving two (2) or three (3) lots are exempt from the requirements of this subsection.

(d)    Nonresidential driveways are prohibited from taking access from an urban access road as defined in Table 40.350.030-2 unless no access exists or can be provided to a collector.

(2)    Driveway Number and Width. A maximum of two (2) driveways may be permitted to a residential lot or individual duplex unit meeting the spacing requirements of Section 40.350.030(B)(4)(b). Joint-use driveways may be allowed and will count as a driveway for each residential lot or duplex unit. For a joint-use driveway, a minimum of a twenty (20) foot wide easement is required. Driveways shall have a minimum width of twelve (12) feet of clear unobstructed all-weather driving surface and an overhead clearance of thirteen (13) feet, six (6) inches. The first, or only, driveway shall be twelve (12) feet to thirty-five (35) feet in width. If a second driveway is allowed, the maximum width of the second driveway will be fifteen (15) feet.

(3)    Driveway Length.

(a)    All portions of shared driveways off of short cul-de-sac roads shall be within three hundred (300) feet of the intersection of the short cul-de-sac with a higher classified road as measured to the intersecting street’s face of curb; provided, that such driveways are subject to Fire Marshal approval.

(b)    All new driveways longer than three hundred (300) feet shall be provided with an approved turnaround at the terminus. There shall also be approved turnouts constructed such that the maximum distance from turnout to turnout, or from turnout to turnarounds, does not exceed five hundred (500) feet. Turnouts shall comply with the Standard Details Manual. Construction of roads and driveways within the wild land urban interface/intermix area shall conform to Section 15.13.030.

(4)    Maximum Dwelling Units Served by Access Roads.

(a)    No road may serve more than one hundred (100) lots or dwelling units unless that road is connected by a second vehicle access road to the same “feeder” road at a different location, or to another “feeder” road that functions at a level equal to at least an urban local residential access road or a rural local access road. The second vehicle access road may be a county emergency-only access road, if it serves less than two hundred (200) lots or dwelling units.

    The second access may be satisfied through the use of an existing roadway network in the existing adjacent neighborhood if:

(i)    An existing road was previously stubbed indicating intent for future access; or

(ii)    An easement has been dedicated specifically for such purpose, and a roadway has been built to county standards or will be constructed with the development to county standards.

    In either case, the increase in traffic volume on the existing roadway network must not cause the traffic volume to exceed the design volume of the existing roadway network.

(b)    Urban neighborhood circulator roads within a development which meet the access requirements above may serve up to three hundred (300) lots or units if approved by the review authority. However, the review authority may require a traffic circulation study showing a balanced traffic flow of less than two thousand (2,000) vehicles per day past any dwelling unit accessing on a neighborhood circulator road or lesser classification upon full buildout.

(c)    When required emergency or regular secondary access roads cannot be installed due to location on property, topography, waterways, nonnegotiable grades or other similar conditions, the County Fire Marshal may require additional fire protection as specified in Title 15 of this code.

(d)    The standards contained in Section 40.350.030(B)(4)(b)(4) are waived in their entirety for developments in rural areas.

(5)    Exceptions.

(a)    The review authority may grant an exception to the requirements of Section 40.350.030(B)(4)(b)(3) to extend the maximum distance between turnouts/turnarounds or allow other appropriate relief where it is impractical or excessively costly to meet these requirements due to topography, sensitive areas, natural features, or where application of these standards would be disproportional.

(b)    The review authority may grant an exception to the requirements of Section 40.350.030(B)(4)(b)(4)(a) in the case of a subdivision with more than one (1) phase, when it can be shown that the other necessary access roads will be constructed in a future phase of the same subdivision. Street stubs built to the property line of property not under the developer’s control do not qualify for such an exception.

c.    Access to Collectors.

(1)    In order to limit the number of residential roads intersecting with collectors while providing adequate neighborhood circulation, residential roads intersecting with collectors shall be classified and constructed to standards applicable to local residential access roads unless the review authority finds that a lesser classification adequately provides for the circulation needs of the surrounding area. Road approach permits not associated with development shall be reviewed using a Type I process.

(2)    Driveways.

(a)    Urban Collectors. No residential driveways in the urban area will be permitted to access collectors unless no other access to the site exists or can be made available.

(b)    Rural Collectors. Residential driveways in the rural area will not be permitted to access collectors if direct lot access is available to an existing rural access road as defined in Tables 40.350.030-2 and 40.350.030-3.

(c)    Spacing. When driveways on collectors are permitted, they shall be spaced in accordance with Table 40.350.030-4. The distance between adjacent one (1) way driveways with the inbound drive upstream from the outbound drive may be one-half (1/2) the distance shown. Where raised channelization exists, only those driveways on the development side of the road will be considered for minimum separation requirements.

(d)    Number of Driveways. The number of driveways and driveway lanes shall be based upon an estimate of site traffic generation in accordance with Table 40.350.030-5. Multiple driveways are not permitted until the estimated ADT exceeds the number shown in the second column for the different types of land use. Then, an additional driveway is allowed each time the estimated ADT increases above the previous maximum ADT for each driveway as shown in the third column; provided, the additional driveways meet the spacing requirements specified in Table 40.350.030-4. Two (2) driveway exit lanes are allowed when the ADT exceeds seven hundred (700).

(e)    Width. A single-family residential driveway onto a collector shall be fifteen (15) to thirty-five (35) feet in width; provided, that a joint-use driveway serving two (2) residential lots shall not exceed thirty-six (36) feet in width. A nonresidential two (2) way driveway onto a collector shall be twenty-four (24) to forty (40) feet in width.

(f)    Corner Clearance. To provide adequate corner clearance, the tangent curb length between the nearest edge of a driveway on an intersecting side street and a collector roadway, or a driveway on a collector roadway and an intersection with a cross street, shall be fifty (50) feet. Where the intersection is signalized or is planned for signalization, driveways shall be limited to right-turn movements if located within one hundred twenty-five (125) feet on a collector or as provided for in Section 40.350.030(B)(4)(d)(2).

(g)    Temporary Driveway. A temporary driveway may be allowed when, due to conditions beyond the control of the applicant, minimum driveway separation cannot be achieved at the time of application. The review authority may approve a temporary driveway when an access plan shows future removal of the temporary driveway and a new driveway which meets the spacing standards shown above.

(3)    Additional Improvements. The installation of other improvements such as left-turn lanes, right-turn lanes and traffic signals may be required by the County Engineer where found necessary on the basis of a traffic engineering study. The study shall address operations of the driveway or intersection, including the adequacy of vehicular turning movements.

d.    Access to Arterials. In order to limit the number of residential roads intersecting with arterials while providing adequate neighborhood circulation, residential roads intersecting with urban arterials shall be classified and constructed to standards applicable to local residential access or collector roads unless the review authority finds that a lesser classification adequately provides for the circulation needs of the surrounding area. In those cases in which an urban access street is less than thirty-six (36) feet wide, such street shall have a minimum width of thirty-six (36) feet at the intersection with the arterial and shall be tapered as shown on the standard plans. Road approach permits not associated with development shall be reviewed using a Type I process.

(1)    Driveways. No driveways will be permitted to access onto urban or rural arterials unless no other access to the site exists or can be provided.

(a)    Spacing. When driveways on arterials are permitted, they shall be spaced in accordance with Table 40.350.030-4.

(b)    Number of Driveways. Where permitted, the number of driveways and driveway lanes on arterials shall be based upon an estimate of site traffic generation in accordance with Table 40.350.030-6.

(i)    Multiple driveways are not permitted until the estimated ADT exceeds the number shown in the second column for the different type of land use. Then, an additional driveway is allowed each time the estimated ADT increases above the previous maximum ADT for each driveway as shown in the columns for minor arterials and principal arterials; provided, the additional driveways meet the spacing requirements specified in Table 40.350.030-4. As an example, a commercial land use on a minor arterial has one (1) driveway up to two thousand (2,000) ADT, then two (2) driveways for two thousand one (2,001) to five thousand five hundred (5,500) ADT, three (3) driveways for five thousand five hundred one (5,501) to nine thousand (9,000) ADT and so on.

(ii)    A permit for exclusive use of a truck driveway in addition to the nontruck traffic may be granted for commercial uses that exceed thirty thousand (30,000) square feet of gross floor space.

(iii)    Two (2) driveway exit lanes are allowed when the ADT exceeds one thousand (1,000).

(c)    Width. A single-family residential driveway onto an urban arterial shall be fifteen (15) to thirty-five (35) feet in width; provided, that a joint-use driveway serving two (2) residential lots shall not exceed thirty-six (36) feet in width. A commercial and multifamily two (2) way driveway onto an arterial shall be twenty-four (24) to forty (40) feet in width.

(d)    Corner Clearance. To provide adequate corner clearance, the tangent curb length between the nearest edge of a driveway on an intersecting side street and an arterial roadway, or a driveway on an arterial roadway and an intersection with a cross street shall be fifty (50) feet. Where the intersection is signalized or is planned for signalization, driveways shall be limited to right-turn movements if located within two hundred fifty (250) feet on minor and principal arterials or as provided for in Section 40.350.030(B)(4)(d)(2).

(e)    Temporary Driveway. A temporary driveway may be allowed when, due to temporary conditions beyond the control of the applicant, minimum driveway separation cannot be achieved at the time of application. The review authority may approve a temporary driveway when an access plan shows future removal of the temporary driveway and a new driveway which meets the spacing standards shown above is assured to be constructed.

(2)    Additional Improvements. The installation of other improvements such as left-turn lanes, right-turn lanes and traffic signals may be required by the County Engineer where found necessary on the basis of a traffic engineering study. The study shall address operations of the driveway or intersection, including the adequacy of vehicular turning movements.

(3)    Medians and Channelization Policy. In order to preserve capacity and promote safety, urban arterials shall generally include raised medians to restrict cross traffic movements. In general, full-access intersections, signalized and nonsignalized, on arterials will be permitted only with other county, state and city roads as are designated on the Arterial Atlas, as amended. Circulation from such intersections in most cases will satisfy the access needs of adjacent land.

    The County Engineer is solely responsible for decisions regarding the placement of raised medians on county roads. Any decision by the county that a raised median will not be installed on an arterial will require a specific determination by the County Engineer that (a) the roadway will operate safely without a raised median and (b) that the roadway will operate at the required capacity without a raised median. Other factors to be considered by the County Engineer include, but are not limited to, the traffic volumes and speeds on the roadway, the crash history on the roadway, roadway geometric factors and other characteristics, and the adequacy of sight lines and distances. Additionally, the number of fronting driveways, the traffic volumes on those driveways, the likely adverse impacts on fronting and other properties, the extent of access control along the arterial, and the number and location of other accesses available to those properties will be considered.

    For commercial zones, raised medians will not be required on arterials where the average weekday traffic is projected to be less than twenty thousand (20,000) vehicles per day over the next five (5) year period and where the County Engineer makes the determination that the roadway will operate safely and without operational problems.

e.    Access to State Routes. If the access serving a development is onto a state road or highway, required dedication and/or improvements thereto must meet the requirements of the Washington Department of Transportation. In no case may the requirements be less than the access requirement to a principal arterial in urban areas or a major collector in rural areas.

Table 40.350.030-4. Driveway Spacing on Arterials/Collectors

Arterial and Collector Posted Speed (MPH)

Minimum Separation (Feet)

20

85

25

105

30

125

35

150

40

185

45 and over

230

(Amended: Ord. 2007-09-13; Ord. 2012-05-14)

Table 40.350.030-5. ADT Carried by Each Driveway onto Collectors

 

ADT for First Driveway

Maximum ADT for Each Additional Driveway

Access from:

 

 

Commercial use

0 to 1,000

2,000

Office use

0 to 1,500

2,000

Multifamily use

0 to 1,000

2,000

Industrial use

0 to 1,500

2,000

(Amended: Ord. 2007-09-13; Ord. 2012-05-14)

Table 40.350.030-6. ADT Carried by Each Driveway onto Arterials

 

 

Maximum ADT for Each Additional Driveway

Access from:

ADT for First Driveway

Minor Arterial

Principal Arterial

Commercial use

0 to 2,000

3,500

5,000

Multifamily use

0 to 1,500

3,000

5,000

Industrial use

0 to 1,500

3,000

4,000

(Amended: Ord. 2007-09-13; Ord. 2012-05-14; Ord. 2012-12-14)

5.    Frontage Roads/Improvement.

a.    General Requirement. Unless already fully developed to the transportation standards and subject to the limitations set forth in this section and in Sections 40.350.030(B)(15) and 40.550.010, a partial-width road shall be established and constructed to the applicable right-of-way or easement and improvement standards set out in Section 40.350.030 to that portion of a frontage public or private road which abuts a parcel being developed as a condition of development approval.

(1)    The right-of-way or easement width shall be a minimum of one-half (1/2) of that specified in Tables 40.350.030-2 and 40.350.030-3; provided, that such minimum width may be increased where necessary to accommodate the minimum roadway improvement provided below to allow a minimum three (3) feet of right-of-way beyond the back of the sidewalk for urban public roads unless the sidewalk is detached from the curb with sufficient room to provide for utilities and signing, or for needed construction clearance, slopes or other features.

    In the case of a development containing an urban arterial or fronting on an urban arterial street, the developer shall only be required to construct improvements up to forty-four (44) feet in width, or twenty-two (22) feet on a partial-width frontage, together with curbs and sidewalks, unless a wider section is necessary to accommodate the development.

    Sufficient right-of-way and easement for a partial-width road must be provided to accommodate all necessary appurtenances required for construction including, but not limited to, approved cut or fill slopes or retaining structures if needed. If sufficient right-of-way is not available, slope easements from neighboring properties are an acceptable alternative. Such easements shall be recorded with the final plat. The county may require the proposed road cross-sections showing neighboring topography be submitted in order to determine if the partial-width road can be constructed as required.

(2)    Partial-width roadways shall be a minimum of twenty (20) feet wide; provided, that curb extensions, when allowed under Section 40.350.030(B)(3)(b)(2)(b)(iv)(c), may reduce the minimum traveled way width on urban local roads to no less than sixteen (16) feet.

(3)    New partial-width roads will be allowed in commercial, office or industrial developments only after a traffic study verifies the adequacy of the roadway for clearance and turning movements.

(4)    Where physical obstructions or development constraints preclude or limit full completion of the frontage road on the abutting property, the partial-width roads may be allowed.

(5)    Parking shall be prohibited along partial-width roads, with signs and pavement markings being the responsibility of the developer unless the partial-width road is at least twenty-four (24) feet wide to provide a clear sixteen (16) foot wide traveled way in addition to an eight (8) foot wide parking lane.

(6)    Where frontage improvements are required, the county will perform pavement deflection testing to determine the adequacy of the existing pavement. Where remaining life of the pavement is less than five (5) years, the developer shall construct the roadway to current standards to the centerline or twenty-two (22) feet, whichever is less. If remaining life is greater than five (5) years, the road shall be cut back to a location where the structure is sound and the widening constructed. However, in no case shall the reconstruction be less than four (4) feet in width from the existing edge of pavement to the new edge of pavement or face of curb. The county may require reconstruction to the centerline or twenty-two (22) feet, whichever is less, if the review authority determines the geometrics or other existing features are inadequate.

(7)    The intersection of driveways with paved rural public roads shall be paved from the edge of the public road to the right-of-way or to twenty (20) feet from the edge, whichever is greater.

b.    Exceptions.

(1)    The right-of-way and easement requirements of Section 40.350.030(B)(5)(a) shall not apply to the construction, remodeling or enlargement of any Group R-Division 3 (single-family or duplex), or Group U occupancy (as defined in the International Building Code), to the construction of any accessory residential structure, to any sign, or to the structural addition, alteration or repair to any existing structure within any twelve (12) month period which neither exceeds twenty-five percent (25%) of the value of the existing structure nor increases the total floor space of the structure by more than ten percent (10%).

(2)    The roadway frontage improvement requirements of Section 40.350.030(B)(5)(a) shall not apply to:

(a)    Rural developments not located within rural centers; or

(b)    Urban or rural center developments which the County Engineer finds, based upon an engineering traffic study, will not result in an increase of total site trip generations during the p.m. peak hour of more than ten percent (10%); provided, that such otherwise exempt developments shall be required to make intersection and sight distance improvements in accordance with Sections 40.350.030(B)(7) and (8) and such frontage road improvements as are necessary in order to provide minimally safe access to the development.

c.    Deferral.

(1)    In the event that required frontage road improvements are included as a portion of a county road project on the county’s six (6) year transportation improvement program scheduled to be undertaken within six (6) years, the developer, in lieu of constructing or guaranteeing the construction pursuant to Section 40.350.030(C)(4)(i) of such frontage improvements, may be permitted to contribute a proportionate share towards the cost of such county road project by an agreement consistent with the requirements of RCW 82.02.020.

(2)    The development approval authority may defer frontage road improvements, in whole or in part, where the current development proposal is for lots in the R1-5, R1-6, R1-7.5, R1-10 or R1-20 zoning districts larger than one (1) acre and a covenant running with the land is recorded requiring such improvements to be undertaken when redivision is proposed at an urban density.

6.    Off-Site Road Improvement.

a.    General. Nothing in this section shall be construed to preclude denial of a proposed development where off-site road conditions are inadequate to provide a minimum level of service as specified in Section 40.350.020 or a significant traffic or safety hazard would be caused or materially aggravated by the proposed development; provided, that the applicant may voluntarily agree to mitigate such direct impacts in accordance with the provisions of RCW 82.02.020.

b.    Requirements for Off-Site Access Road Improvements. All roads providing access to parcels being developed, whether such roads are to be public or private, shall at a minimum:

(1)    Within the urban area have an unobstructed and paved roadway width of twenty (20) feet, or eighteen (18) feet of pavement with one (1) foot wide shoulders. Any pre-existing roadway narrower than eighteen (18) feet with one (1) foot shoulders shall be widened to the full twenty (20) foot standard. Those portions of a roadway reduced in width due to curb extensions allowed under Section 40.350.030(B)(5)(a)(2) are not required to meet the above requirement, provided a minimum of sixteen (16) feet of pavement is provided.

(2)    Within the rural area, off-site public access roads shall meet the same standards as Section 40.350.030(B)(6)(b)(1). Off-site private access roads are not required to be paved but shall have an all-weather driving surface, unobstructed roadway width of twenty (20) feet; except in those cases where the pre-existing road is eighteen (18) feet wide, additional widening to twenty (20) feet is not necessary. Any pre-existing roadway narrower than eighteen (18) feet shall be widened to the full twenty (20) foot standard.

(3)    Have an unobstructed vertical clearance of not less than thirteen (13) feet six (6) inches (13' 6").

(4)    Notwithstanding the foregoing, roads providing access to legal lots created prior to July 9, 1996, being developed with a Group R-Division 3 structure or residential mobile home, may be constructed with a minimum twelve (12) foot wide unobstructed all-weather driving surface.

(5)    Off-site private roads providing access to lots being developed shall have a minimum easement partial width of twenty-five (25) feet from such lot to a public road.

c.    Requirements for Off-Site Intersection Improvement. The owners of a parcel being developed shall enter into a signal participation agreement to contribute a proportionate share towards the cost of a traffic signal when:

(1)    An intersection impacted by the proposed development is designated by the county for installation of a traffic signal; and

(2)    The parcel being developed is not located within a traffic impact fee (TIF) service area; and

(3)    During the peak hour, the development generates a minimum of three percent (3%) increase of traffic on the intersection approach leg impacted by the development, or five (5) trips on a minor leg (those legs of the intersection that have the smaller approach volume) or twenty (20) trips on a major leg (those legs of the intersection that have the larger approach volumes); and

(4)    The peak hour level of service at the leg of the intersection impacted by the site-generated traffic is at or will fall below the minimum level of service standard for that intersection as defined in Section 40.350.020.

7.    Intersection Design.

a.    Intersection Geometry. Private and public roads shall be laid out so as to intersect at an angle as near to a right angle as practicable, but in no case less than seventy-five (75) degrees for roads intersecting collectors and arterials and no less than sixty (60) degrees for access roads, unless modified pursuant to Section 40.550.010. Opposing roads accessing an intersection shall either be aligned or will be separated by a minimum intersection spacing, as specified in Table 40.350.030-3. Depending on the width of the intersection opening, an off-set greater than ten (10) feet for access roads or five (5) feet for collectors and arterials is not allowed.

b.    Intersection Right-of-Way.

    Intersections shall have a minimum corner radius of ten (10) feet along the right-of-way lines for access roads and a minimum corner radius of twenty-five (25) feet along the right-of-way lines for collectors and arterials, unless road improvements require a greater radius.

    On collectors and arterials, the dedication of right-of-way on corners shall include the chord of the radius. The county will accept an easement for this chord instead of dedication of right-of-way. For arterials intersecting with other arterials, an additional six (6) feet right-of-way may be required on both sides of the roadway if a future turning lane is required, based on transportation impact study, within twenty (20) years from the time an application is submitted. The length of the additional right-of-way shall be determined based on the transportation impact study.

c.    Paving of Intersecting Area.

    Where connecting to a paved street, whether public or private, the connecting road or driveway (excluding driveways in rural area) shall be paved twenty-five (25) feet back from the nearest edge of the traveled lane, or shall be equal to the minimum intersection radii as specified in Table 40.350.030-3, whichever is greater.

    Driveways in rural areas connecting with paved public roads shall be paved from the edge of the public road to the right-of-way or to twenty (20) feet from the edge, whichever is greater.

    Rural paving shall be done in accordance with the equivalent base structural requirements of the gravel road section as noted in the Standard Details Manual.

8.    Sight Distances. As noted in Section 40.350.030(A)(2), this subsection also applies to applications for building permits and applications for access to public roads. Unless modified pursuant to Section 40.550.010, public and private roads shall comply with the following sight distance requirements:

a.    Stopping Sight Distance.

    Intersection sight distance and stopping sight distance values are based on the default assumption of level grades, normally intersecting roadways, and with passenger cars as the design vehicle. When deviating from the default assumptions, the engineer shall take the roadway grades, intersection skew, and design vehicle classification into consideration when calculating the required intersection sight distance and/or stopping sight distance.

    Public roads shall have minimum stopping sight distance, as measured from a height of three and one-half (3.5) feet to a target on the roadway nominally two (2) feet in height, in accordance with Table 40.350.030-7. The effect of grades on stopping sight distance shall be calculated using the most current version of the Washington State Department of Transportation’s “Design Manual.”

    For unposted roadways, the legal speed limit shall be fifty (50) mph per the “Basic rule” under RCW 46.61.400.

Table 40.350.030-7. Stopping Sight Distance

Speed (mph)

Minimum Stopping Distance (feet)

25

150

30

200

35

250

40

325

45

400

50

475

(Amended: Ord. 2012-05-14; Ord. 2014-01-08)

b.    Controlled Intersection and Driveway Sight Distance Triangle.

    Traffic entering an uncontrolled public road from stop controlled public roads, or from private roads or private driveways, shall have minimum intersection sight distances, as shown in Table 40.350.030-8. Sight distance shall be measured from an eye height of three and one-half (3.5) feet above the controlled road pavement surface and fifteen (15) feet from the edge of the vehicle travel lane of the uncontrolled public road. The object height on the uncontrolled public road shall be three and one-half (3.5) feet above the pavement surface located four (4) feet to the right of the striped or assumed centerline of the roadway. For multilane highways, the object on the uncontrolled roadway shall be located on the approach lane closest to the controlled side street. Sight distance triangles shall be clear of all obstructions, including, but not limited to, landscaping, fences, structures and earth berms between the heights of three (3) and seven (7) feet.

Table 40.350.030-8. Controlled Intersection, Public Road and Driveway Sight Distance

Speed, Uncontrolled Road (mph)

Minimum Corner Sight Distance (feet)

20

200

25

250

30

300

35

350

40

400

45

450

50

500

(Amended: Ord. 2012-05-14; Ord. 2014-01-08)

c.    Uncontrolled Intersections.

    Uncontrolled intersections for access roads in urban and rural areas with a posted speed limit of twenty-five (25) mph or less shall have an unobstructed intersection sight distance triangle per Section 40.350.030(B)(8)(b) of one hundred (100) feet on both approaches. This requirement may be reduced to eighty (80) feet for intersections abutting corner lots in an urban residential subdivision. The intersection sight distance shall be measured along the lines four (4) feet from the roadway center, in drivers’ direction, for both approaches.

d.    New urban and rural residential driveways accessing roads with a speed limit of over twenty-five (25) mph are subject to Table 40.350.030-8.

9.    Street Extensions.

a.    General Requirements. Where a public or private road has been constructed, created or stubbed in such a manner as to be able to be extended or widened in accordance with the Clark County Arterial Atlas, other requirements of this section, or prior approved development, the following shall apply:

(1)    Connection with Adjacent Areas. All residences, buildings or structures shall be constructed in such a position on the property that they will not interfere with the extension or widening of the roadway to adjacent areas and shall be so situated that such extension will make orderly and planned development for additional road installations to meet the reasonable minimum requirements of good and safe traffic circulation, consistent with applicable zoning setbacks.

(2)    Right-of-Way for Street Extensions. Right-of-way or private easements necessary to such extension or widening and falling within parcels being developed shall be granted or created as a condition of development approval.

b.    Urban Developments.

(1)    Provisions for Future Extensions. Any street within the urban area for which an extension in the future is planned shall be extended to the edge of the property being developed through the plat, short plat or site plan approval process, unless otherwise approved by the review authority. The street stub shall be a full street section, including sidewalks.

(2)    Use of Temporary Turnaround. If a road serving more than eighteen (18) dwelling units or more than one hundred fifty (150) feet in length temporarily terminates at a property boundary, a temporary turnaround cul-de-sac bulb consistent with this standard shall be constructed near the plat boundary. The bulb shall be paved and shall be eighty (80) feet in diameter, which may include the width of the roadway with sidewalks, where required, terminating at the point where the bulb radius begins. Removal of the temporary turnaround and extension of the sidewalk shall be the responsibility of the developer who extends the road (see the Standard Details Manual). The easement for a temporary turnaround may be extinguished without county approval after the temporary turnaround is determined to be no longer necessary by the county.

(3)    Barricades. A barricade shall be placed at the end of all stub streets, whether or not a temporary turnaround is constructed. For placement of temporary and permanent barricades, see Section 40.350.030(C)(4)(f).

c.    Rural Developments. For any road in the rural area for which an extension is planned, the right-of-way falling within parcels being developed shall be dedicated where the existing platting pattern, the development under review and the potential for development of adjacent lots demonstrates a need for the dedication.

10.    Private Roads.

a.    Purpose. The purpose of private road standards is to provide an option to retain rural character, reduce costs to serve large rural lots, and allow more control, security, and sense of identity when public roads are not needed for public circulation.

    For private road maintenance agreement, private road inspection, and developer maintenance obligation for private roads, see Section 40.350.030(C)(4)(g).

b.    Approval Criteria and Requirements.

(1)    Approval Criteria – General. Private roads are not allowed in either the urban or rural area:

(a)    When they conflict with the Arterial Atlas, as amended; or

(b)    When they are needed for public circulation; or

(c)    When they connect two (2) public roads (except for commercial or industrial uses in urban areas); or

(d)    When they are to serve more than fifty (50) potential residential lots in rural areas or one hundred (100) lots in urban areas, created after April 12, 1994, except within a planned unit development; provided, that where expansion of a public road is not presently feasible, the limitations of this subsection shall not apply if the affected internal and frontage roads are improved to public standards (if otherwise required) and dedicated to the county, with the acceptance of such dedication(s) being deferred until extension of a public road allows connection.

(2)    Additional Requirements for Urban Private Roads. Private roads within developments may be allowed, provided they meet the following additional criteria:

(a)    Structural sections shall be the same as for public roads of equivalent classification;

(b)    A pedestrian access plan shall be approved;

(c)    Internal traffic calming measures or devices such as speed humps or traffic circles may be required; and

c.    Notice. The following statement is required on the face of any site plan, or binding site plan or within the Developer Covenants to Clark County for any subdivision or short plat containing a private road: “Clark County has no responsibility to improve or maintain the private roads contained within or private roads providing access to the property described in this development. Any private access street shall remain a private street unless it is upgraded to public street standards at the expense of the developer or abutting lot owners to include hard surface paving and is accepted by the county for public ownership and maintenance.”

d.     Private bridges are addressed in Section 40.350.040.

11.    Joint Driveways. A maximum of four (4) legal lots may use a joint driveway to access a public or private road.

12.    Cul-de-Sacs and Turnarounds.

a.    Cul-de-Sacs.

(1)    Short Cul-de-Sacs. The minimum right-of-way diameter across the bulb section is seventy (70) feet, with a minimum pavement diameter across the bulb section of sixty (60) feet. Rolled curb and gutter and thickened sidewalk shall be constructed in accordance with the Standard Details Manual.

(2)    Whenever a residential urban cul-de-sac street is more than one hundred fifty (150) feet long, a bulb or hammerhead shall be constructed as follows:

(a)    Standard Cul-de-Sac Turnarounds. The minimum right-of-way diameter across the bulb section is one hundred (100) feet, with a minimum pavement diameter across the bulb of ninety (90) feet. Alternatively, right-of-way may be reduced to eighty (80) feet, with a paved diameter across the bulb of seventy (70) feet, provided rolled curb and gutter with thickened sidewalk is constructed in accordance with the Standard Details Manual.

(b)    Temporary Cul-de-Sacs. Temporary cul-de-sacs shall provide at minimum paved diameter of eighty (80) feet for the bulb. Those portions of the bulb area lying outside the straight-street right-of-way shall be provided as a temporary easement pending extension of the street.

(c)    Urban Cul-de-Sac or Eyebrow Island. Optional feature for any cul-de-sac when the bulb’s paved diameter is ninety (90) feet or less; mandatory when the bulb’s paved diameter exceeds ninety (90) feet. If provided, islands shall have full-depth vertical curbs. Minimum island diameter shall be twenty (20) feet and there shall be at least twenty-two (22) feet of paved traveled way in a shoulder type section; thirty (30) feet of paved traveled way in a curb type section around the circumference. Islands shall be grassed or landscaped. Islands shall be maintained by the adjoining lot owners. Islands are required on eyebrows with a radius greater than thirty (30) feet. The minimum island diameter shall be ten (10) feet.

(3)    In the urban and urban holding areas of the county, a permanent cul-de-sac shall not be longer than six hundred (600) feet measured from curb line of intersecting street to the center of the bulb section. Proposed modifications to this rule will be considered by the review authority based on pertinent traffic planning factors such as topography, sensitive areas and existing development.

(4)    In the rural area of the county, there is no limitation to the length of a dead-end road or cul-de-sac; provided, however, that approved turnarounds on roads greater than one-half (1/2) mile long are provided every one thousand three hundred twenty (1,320) feet or as close to that distance as practical considering topography, natural features and existing manmade structures. Approved turnarounds may include cul-de-sacs, which may include the width of the roadway, intersecting public or private roads, hammerheads, or driveways meeting the dimensional requirements of a hammerhead. Within the wildland urban interface/intermix, approved turnarounds shall be provided every one thousand (1,000) feet. Dimensional requirements for all transportation related features in this subsection are as drawn in the Standard Details Manual.

    Notwithstanding the foregoing, the development approval authority may restrict the length of a dead-end road or cul-de-sac where it is clearly shown that either:

(a)    There is a practical alternative design that 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 a significant potential for isolating a substantial area from emergency services.

(5)    The review authority 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.

b.    Turnarounds.

(1)    When four (4) or more lots are served on a private road greater than one hundred fifty (150) feet in length, an approved turnaround shall be provided at the end of the private road. Easements may be required to be expanded to accommodate turnaround requirements.

(2)    Approved turnarounds may include cul-de-sacs with an approved diameter in accordance with the Standard Details Manual (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 drawn in the Standard Details Manual.

(3)    For those areas identified as wildland urban interface/intermix, refer to Chapter 15.13 as amended.

13.    Urban Neighborhood Traffic Management.

a.    Purposes. Urban neighborhood traffic management is intended to manage traffic speeds within residential neighborhoods and to discourage external traffic cutting through residential neighborhoods.

b.    Applicability. The provisions of this section shall apply only to access roads within a development in the R1-5, R1-6, R1-7.5, R1-10, R1-20, R-12, R-18, R-22, R-30, R-43, OR-15, OR-18, OR-22, OR-30, OR-43, CR-1, CR-2, or MX zoning districts which meet one (1) of the following conditions:

(1)    Projected average daily trip of greater than six hundred (600) and less than two thousand (2,000) motor vehicles and a sight distance in excess of six hundred (600) feet; or

(2)    Determined by the County Engineer, not his or her designee, that traffic calming measures and/or traffic calming devices are warranted.

    The review authority may waive the requirements of this section for Type I and Type II applications where the conditions listed above will not occur.

c.    Standards and Requirements. If the condition in Section 40.350.030(B)(13)(b) occurs, traffic calming measures and/or traffic calming devices shall be required:

(1)    Traffic Calming Measures. Traffic calming measures, such as “T” intersection, street trees, curvilinear streets, or entry treatments, shall be incorporated into the overall development design to manage traffic speeds.

(2)    Traffic Calming Devices. Traffic calming devices, such as speed bump/hump and the devices shown in the Standard Details Manual or as approved by the review authority, shall be installed.

14.    Urban Transit Circulation Standards. New residential, commercial and industrial developments shall be reviewed with the participation of C-TRAN invited during the development review process under Subtitle 40.5 to ensure appropriate design and integration of transit facilities into the development.

15.    Right-of-Way Standards. Dedication of arterial right-of-way shall occur within developments in accordance with the transportation element of the comprehensive plan.

a.    Public Roads. The minimum right-of-way and roadway widths for all public urban and rural roads shall be as shown on the design criteria detailed in Section 40.350.030(B)(3). Right-of-way widths, roadway widths and structural sections shall be consistent with projected traffic volumes planned for twenty (20) years from the time of design. Additional right-of-way or easement may be required where necessary to accommodate slopes, sight distance or other features necessary for maintenance or to enhance safety.

b.    Urban Planned Unit and Multifamily Developments. When constructed, public roads shall be constructed according to the design criteria of Section 40.350.030(B)(3); provided, parking may be deleted when it is shown that four (4) non-tandem off-street parking spaces per unit are provided and distinct signs and markings show that no parking is permitted; and sidewalks along internal circulation roadways may be deleted by the review authority when it is shown that public walkways adequate for pedestrian circulation and meeting or exceeding the requirements of Section 40.350.010 are provided.

c.    Commercial, Office Campus and Industrial Areas. When constructed, public roads shall be constructed according to the design criteria of Section 40.350.030(B)(3). The structure of the road shall be designed according to minor arterial standards.

(Amended: Ord. 2004-06-11; Ord. 2005-04-12; Ord. 2006-09-13; Ord. 2006-11-07; Ord. 2006-11-15; Ord. 2007-09-13; Ord. 2007-11-13; Ord. 2008-06-02; Ord. 2009-03-02; Ord. 2009-07-01; Ord. 2009-12-01; Ord. 2012-05-14; Ord. 2012-05-30; Ord. 2012-07-03; Ord. 2012-12-23; Ord. 2014-01-08)

C.    Specifications for Design and Construction.

1.    Transportation Standard Specifications.

a.    Transportation Standards.

    The standards for Clark County roads and bridges, and all other construction within publicly owned rights-of-way, shall consist of:

(1)    The current published edition of the Standard Specifications for Road, Bridge and Municipal Construction as published by the Washington Department of Transportation (WSDOT) and the American Public Works Association (APWA) referred as Standard Specifications;

(2)    The current Standard Plans for Road and Bridge Construction as published by WSDOT and APWA (referred as Standard Plans); and

(3)    The Standard Details Manual as defined in Section 40.100.070, and issued by the County Engineer, containing typical drawings to implement transportation, erosion control, drainage, and other engineering standards adopted in the Clark County Code.

b.    Supplemental Standards. To implement the above standards, the following publications and their subsequent revisions are adopted and shall apply:

(1)    The WSDOT Design Manual;

(2)    The WSDOT Construction Manual;

(3)    The WSDOT Hydraulics Manual;

(4)    A Policy on Geometric Design of Highways and Streets prepared by the American Association of State Highway and Transportation Officials (AASHTO);

(5)    The Manual on Uniform Traffic Control Devices (MUTCD) prepared by the U.S. Department of Transportation, Federal Highway Administration;

(6)    Chapter 40.385, Stormwater and Erosion Control;

(7)    Chapter 51-304 WAC, State of Washington adoption of the Americans with Disabilities Act into the International Building Code; and

(8)    The AASHTO LRFD Bridge Design Specifications, U.S. Customary Units, including its commentary (refer to Section 40.350.040, Private Bridges, for exceptions to this manual).

c.    Conflict of Standards. In the event of conflict with any of the specifications, the County Engineer shall specify which of the supplemental specifications will apply.

2.    Construction Plan Requirements for Transportation and Utility Improvements. The applicant shall submit to the responsible official plans and specifications for street and utility construction for the proposed development. The plans and specifications shall include a vicinity map, a plan and profile, special provisions, and reference to the standard specifications, including the typical sections.

a.    The Plan. The plan shall include the road alignment at a scale of not less than one (1) inch to fifty (50) feet (where less detail is required, a scale of one (1) inch to one hundred (100) feet may be approved by the responsible official) showing centerline stationing on all intersecting streets, with bearings on centerlines; curve data on all horizontal curves; right-of-way; relevant topography; existing and proposed utility location; street names in the development and adjoining the development; typical roadway section showing placement of utilities; existing and proposed drainage and water quality appurtenances; sidewalk ramp locations; floodplain and wetland boundaries; signalization, channelization, striping and signing; sufficient topographic data adjacent to the site to identify cut and fill limits from the proposed improvements and such further data as may be required by the responsible official.

b.    The Profile. The profile shall show the relevant original ground lines using the same stationing as in the plan, control elevations, grade line showing the proposed grades, vertical curves, all bench marks, the vertical datum, and such further information as may be reasonably required by the responsible official. For new streets, the relevant original ground lines will show the ground line at centerline at a minimum and also at the edges of the right-of-way if grade differences are significant (or alternatively, surveyed contour lines on the plan view). For existing street, the applicant shall also show the ground line at the edge of pavement or face of curb, whichever is applicable. The profile lines for roads extending to the perimeter of any development shall be extended a minimum of three hundred (300) feet beyond the perimeter to include any change in contours which would affect the profile of the extension of the proposed road. If vertical control is available within one-half mile of the project, the applicant shall use the National Geodetic Vertical Datum of 1929 (1947 adjustment) as a vertical datum. If county horizontal control, based on the North American Datum of 1983 (1991 adjustment), is available within one-half (1/2) mile of the project the applicant shall make a tie to the grid bearing and coordinate of the datum.

c.    Required Project Construction Notes. Any required construction notes shall be shown or referenced on the plans.

d.    Format. The cover sheet of all plans shall include a statement identifying which standard specifications will apply to the project. Plan and profile may be shown on the same sheet with profiles shown on the bottom half of the sheet. Sheets shall measure twenty-two (22) to twenty-four (24) inches in height by thirty-four (34) to thirty-six (36) inches in length with a borderline of one and one-half (1.5) inches on the left side of the length of the sheet and one-half (0.5) inch on remaining sides. When more than two (2) plan sheets are used, an overall development layout shall be submitted showing the relationship of roads and utilities.

(1)    A north arrow shall be shown on each plan view sheet of the plans and adjacent to any other drawing which is not oriented the same as other drawings on the sheet.

(2)    Character size shall not be smaller than eight one-hundredths (0.08) inch high.

(3)    All detail drawings shall be included in the drawings.

(4)    A title block shall appear on each sheet of the plan set and shall be placed in the lower right-hand corner of the sheet, across the bottom edge of the sheet or across the right-hand edge of the sheet. The title block shall include the name of the project, the engineering firm, the sheet title and the owner if not shown on the first sheet.

3.    Transportation Design Specifications. The design criteria set out Tables 40.350.030-2 and 40.350.030-3 are adopted as a portion of the Clark County Standard Specifications. Such criteria are applicable to roads located within and adjacent to a development. These criteria are intended for normal conditions. The responsible official may require higher standards for unusual site conditions.

a.    Typical Roadway Section. The typical roadway section shall be as shown on the county standard plans. The roadway section used shall be detailed on the construction plans submitted for each new roadway or improvement to an existing roadway. Any deviation from the “Standard Plans” for typical cross-section will require a modification pursuant to Section 40.550.010.

b.    Required Details. The typical section shall show the width of right-of-way, width of roadway, type and compacted depth of surfacing and paving materials, and such other dimensions as may be necessary or required. The location and width of sidewalks, walkways, curbs or curb and gutter shall also be shown, where applicable.

c.    Surfacing – Depth Determination. The depth of surfacing and paving materials shall be determined from the standard plans. The depth to be used shall be determined from the functional use classification of the road to be improved and the AASHTO soil classification as shown in the Soil Survey of Clark County, Washington, published by the U.S. Department of Agriculture, Soil Conservation Service. In the case where the applicant wishes to submit an alternative surfacing and paving depth design, the applicant shall provide a design to support the proposed depths. The County Engineer shall establish and maintain criteria and methodologies for performing alternative surfacing and pavement depth design, including verified soil engineering characteristics and traffic loadings for approving such alternative designs.

d.    Alternate Surface Treatment. Alternate surface treatments, other than permeable pavement, may only be used upon approval of the County Engineer. The applicant shall supply the County Engineer with specifications for materials and application rates as part of the approval. Permeable pavement is allowed under Section 40.350.030(B)(3)(b)(1)(a), subject to the specifications in the current edition of the LID Technical Guidance Manual.

e.    Steeper Grades. Roads constructed in grades steeper than fifteen percent (15%) shall be constructed with Portland cement concrete, with grooved surfacing. Rural roads are exempted from this requirement.

f.    Grades and Drainage. Access road drainage facilities shall be designed to meet the requirements of the county stormwater drainage and erosion control ordinances, and be sufficient to prevent water damage or impairment from normal rain flow or surface water. Erosion control shall be provided during construction to maintain the roadways such that mud and debris are minimized consistent with such ordinances.

    Drainage details and street profile grades shall be shown on the construction plans. In the urban and urban reserve areas, the centerline profile street grades shall not be less than one percent (1%) unless an integral curb and gutter section is used, in which case the minimum grade shall not be less than three-tenths percent (0.3%). If any grading or filling to lots or other areas outside the streets is to be done which exceeds those amounts specified in Chapter 14.07, an overall grading plan shall be submitted as a part of the plans. In rural area, driveway culverts must be a minimum of twelve (12) inches. Culverts larger than the minimum will be sized by identifying the size of culverts upstream.

g.    Passing Sight Distance. Arterial roads shall have minimum passing sight distance, as measured from a height of three and one-half (3.5) feet to an object of four and one-quarter (4.25) feet in height, in accordance with Table 40.350.030-9. The effect of grades on the sight distances shall be governed by the criteria stated in the American Association of State Highway and Transportation Officials’ (AASHTO) reference “A Policy on Geometric Design of Rural Highways (1990).”

Table 40.350.030-9. Passing Sight Distance

Design Speed (mph)

Minimum Passing Distance (feet)

30

1,100

35

1,300

40

1,500

45

1,650

50

1,800

(Amended: Ord. 2012-05-14)

h.    Signing.

(1)    General Requirement. The developer shall reimburse the county for the installation of all necessary street name signs, warning signs and regulatory signs. The cost of all signs, barricades, and pavement markings will be determined on a time and materials basis.

(2)    Private Road Signs. Private road signs with street designations shall be provided by the developer at the intersection of private roads with private and public roads. Such signs shall meet the specifications shown on the typical drawing and, in the case of intersections with public roads, shall either be located within the public right-of-way or within a separate maintenance easement. Road signs shall be included in the private road maintenance agreement.

4.    Transportation Construction Specification.

a.    General. No construction shall begin until plans have been approved by the county, except that rough grading operations may proceed before the plans are approved under the following conditions:

(1)    The grading plan is submitted separately along with an application for a grading permit, if required;

(2)    The grading plan is in conformance with the approved preliminary plat or other development approval;

(3)    The grading plan will not be in conflict with the street and drainage plans; and

(4)    Any required grading permit is issued. No utility installation is allowed under grading permits.

    The responsible official shall be notified not less than forty-eight (48) hours prior to the start of any phase of construction.

b.    Subgrade. The subgrade must be inspected and approved by the responsible official prior to application of the crushed surfacing material.

c.    Crushed Surfacing Materials. The standard specifications shall apply to all materials and workmanship. Compaction of subgrade and surfacing materials shall be in accordance with the WSDOT Standard Specifications. The subgrade and crushed surfacing materials shall be compacted to ninety-five percent (95%) of the maximum density for the material. The base course shall be approved prior to application of top course, and top course shall be approved prior to placement of pavement. Approval shall be by the responsible official.

d.    Paving. The standard specifications shall apply to all materials and workmanship. The department shall be notified not less than forty-eight (48) hours in advance of the application of any type of paving and, in accordance with the standard specifications, the responsible official may stop or delay paving operations when the weather or other conditions indicate that suitable results may not be obtained.

e.    Trench Backfill.

(1)    Trench Backfill for Construction. All trench backfill within the county right-of-way and the road improvement area shall be imported gravel backfill meeting the material specification of the WSDOT Standard Specifications Section 9-03.19. Native soils may be utilized upon the responsible official’s approval if testing shows the material is classified as A-1 or A-3 by AASHTO. Trench backfill shall be compacted within the roadway prism to ninety-five percent (95%) of maximum density as determined by AASHTO T-99. Areas within the right-of-way and outside the roadway prism may be compacted to ninety percent (90%) of AASHTO T-99. The trench backfill shall be placed in conformance with the Standard Specification Section 7-08.3(3).

(2)    Trench Backfill for Utility. Application of this specification is required on principal and minor arterials, urban collectors, rural major and minor collectors, and any roadway that has been reconstructed or overlaid within two (2) years.

    Utility trenches in existing roadways and which run transverse to the direction of vehicle travel shall be constructed in accordance with the requirements of the utility cut permit, issued from Clark County’s operations division. In addition to the requirements listed in Section 40.350.030(C)(4)(e)(1), tranverse utility cuts will be required to have the top three (3) feet of trench backfill constructed with controlled density fill meeting the requirements of the Standard Specification Section 2-09.3.(1)E. Refer to the Standard Details Manual for examples.

f.    Temporary and Permanent Barricades. Temporary and permanent barricades shall conform to the standards described in Section 6C-8 of the Manual on Uniform Traffic Control Devices (MUTCD). For street extensions, including subtitle connection with adjacent areas, right-of-way for street extension, provision for future extension, and use of temporary turnaround, see Section 40.350.030(B)(9).

(1)    Type I or Type II barricades may be used when traffic is maintained through the area being constructed/reconstructed.

(2)    Type III barricades may be used when roadways and/or proposed future roadways are closed to traffic. Type III barricades may extend completely across roadway (as a fence) or from curb to curb. Where provision must be made for access of equipment and authorized vehicles, the Type III barricades may be provided with movable sections that can be closed when work is not in progress, or with indirect openings that will discourage public entry. When job site access is provided through the Type I barricades, the developer/contractor shall assure proper closure at the end of each working day.

(3)    In the general case, Type III permanent barricades shall be installed to close arterials or other through streets hazardous to traffic. They shall also be used to close off lanes where tapers are not sufficiently delineated.

(4)    Type III barricades shall be used at the end of a local access street terminating abruptly without cul-de-sac bulb or on temporarily stubbed off streets. Each such barricade shall be used together with an end-of-road marker.

(5)    Barricades on dead-end streets which may be extended in the future will have a sign placed upon them, as approved by the responsible official, which gives notice that the road will be extended in the future, and will give a telephone number for interested persons to call to receive more information.

g.    Private Road Maintenance Agreement. The county will not maintain roadways, signs or drainage improvements on private roads. All private roads shall be maintained by the owners of the property served by them and kept in good repair at all times. A private maintenance covenant recorded with the County Auditor will be required for any private road serving more than three (3) lots. The covenant will set out the terms and conditions of responsibility for maintenance, maintenance methods, standards, distribution of expenses, remedies for noncompliance with the terms of the agreement, right of use easements, and other considerations. The covenant shall be submitted to the responsible official for approval prior to recording. The covenants, which may be in the form set forth in the Standard Details Manual, shall include the following terms:

(1)    The covenant shall establish minimum annual assessments in an amount adequate to defray costs of ordinary maintenance and procedures for approval of additional needed assessments.

(2)    The covenant shall include a periodic maintenance schedule.

(3)    The covenants for maintenance shall be enforceable by any property owner served by the road.

(4)    The means shall be established for assessing maintenance and repair costs equitably to property owners served by the private road.

(5)    The covenants shall run with the land.

(6)    “Maintenance” shall include, but not be limited to, road surfacing, shoulders, gates, signs, storm drainage facilities and vegetation control.

(7)    Private Road Inspection. Private roads will be subject to the same inspection schedule as public roads.

(8)    Developer Maintenance Obligation. The developer of a residential plat or short plat shall be responsible to ensure the maintenance of the private road for a period of two (2) years from the date of recording of the plat or short plat. Thereafter, the developer’s maintenance responsibility will depend upon the number of lots under the developer’s continuing ownership, as stated in the recorded maintenance agreement.

h.    Construction of Sidewalks.

(1)    Construction Standards. Materials and construction of sidewalks and accessways shall conform to the standard plans for the type of adjacent road. Sidewalks shall be surfaced with Portland cement concrete. Accessways may be surfaced with Portland cement concrete or two (2) inches of asphaltic concrete pavement on four (4) inches of compacted crushed surfacing. Alternatively, permeable pavement is allowed, subject to the requirements in Section 40.350.030(B)(3)(b)(1)(a).

(2)    Construction Timing. Unless earlier installation is required by the responsible official, required sidewalks and accessways shall be installed in conjunction with either the construction of an adjacent road or the construction of a building structure. That portion of any required sidewalks or accessways adjacent to any lot shall be constructed prior to issuance of a certificate of occupancy for a building constructed on such lot.

(3)    Construction Bond. If the responsible official determines that construction is not feasible when a building is ready for occupancy, a construction bond or other security acceptable to the responsible official shall be posted guaranteeing the construction of required sidewalks and accessways. The amount of such construction bond, or other security, shall be set by the responsible official based upon the estimated cost of installation at the time when the sidewalk or accessway is to be constructed.

(4)    Procedure. Except as modified herein, the reviews, approval, inspection and acceptance procedures established elsewhere in this section shall similarly apply to sidewalks and accessways.

    Note: For sidewalks requirements, see Section 40.350.010(B). For sidewalks detailed specifications, see the Standard Details Manual.

i.    Construction Guarantee. In lieu of the completion of any required public improvements prior to approval of a final plat, short plat or the issuance of building permits, the responsible official may accept a bond, in amount and with satisfactory surety and conditions, or other secure method as the responsible official may require, providing for and securing to Clark County the actual construction and installation of such improvements within a period specified by the responsible official and specified in the bond or other agreement, and to be enforced by the Community Development Director by appropriate legal and equitable remedies. The amount of bond or escrow shall be one hundred percent (100%) of the estimated cost as determined by the responsible official for the county to construct the improvement.

j.    Issuance of Building Permits. Building permits and certificates of occupancy may be issued once the public improvements are substantially completed. In order for a model home/temporary sales office to be constructed, a building permit for one (1) dwelling unit may be issued prior to substantial completion of the public improvements.

    Building permits, other than for Group R-Division 3, may be issued prior to substantial completion if the responsible official finds that the issuance and subsequent building construction does not interfere with emergency accessibility or the completion of public improvements. In this case, certificates of occupancy will not be issued until the public improvements are substantially completed.

k.    Record Drawing. The applicant shall submit a reproducible set of plans for all public improvements showing all construction changes, such as location of culverts, alignment and grade changes, added and deleted items, location of utilities, water valves, stormwater facilities, sewer connections, etc. The record drawings shall be prepared and stamped by a licensed engineer or surveyor, and submitted prior to acceptance of any improvements for provisional maintenance by the county.

l.    Acceptance by County. Roads, drainage, landscaping, irrigation, and any other required right-of-way construction may be accepted for provisional maintenance by the county upon receipt of a workmanship and materials bond (or other secure method) in the amount of ten percent (10%) of the construction cost and the recommendation of the responsible official. Final acceptance will not be made for two (2) years from the date of provisional acceptance and the developer must repair any failure within the two (2) year period. The applicant may request inspection of the constructed facilities for release of the said workmanship and materials bond (or other secure method) at the end of the two (2) year provisional maintenance period.

m.    Construction Revisions and Modifications to Construction Specifications. Revisions made during construction drawing review or during actual construction which do not conflict with conditions of development approval or the road standards may be authorized by the responsible official. Written consent between the responsible official and the developer is required. The developer will be responsible for informing the construction contractor of all approved changes. In unique circumstances the responsible official will consider requests for variation from the above listed construction specifications. It shall be the developer’s responsibility to furnish supporting documentation as required by the responsible official to substantiate the requested variation.

(Amended: Ord. 2006-09-13; Ord. 2007-06-05; Ord. 2007-11-13; Ord. 2009-01-01; Ord. 2009-03-02; Ord. 2009-06-01; Ord. 2012-05-14; Ord. 2012-05-30; Ord. 2014-01-08)