Roadway Standards Section 225 - Roadway Development

225.1 Future Extension of Roadways Related to Development

1. When required by land use approval, a proposed development shall construct a public roadway, or private roadway acceptable to the County, to the boundaries of the development to permit future development or division of adjoining land, in order to promote connectivity.
2. A roadway master plan may be required prior to approval of the location of a roadway stubbed to the current development boundary to ensure connectivity of the future roadway system and to retain the development potential of adjacent land.  This master plan shall consider topographical and geographical information and assume maximum development consistent with existing zoned densities.
3. New public roadways that are stubbed to adjacent property with future potential extension may require the construction of a temporary turnaround, depending on the length of the dead end street and/or the dedication of right-of-way for the temporary turnaround or future turnaround.
4. Public streets that cannot be extended shall end in a County approved cul-de-sac or turnaround. 

225.2 Termination of Roadways/Dead End Streets (Cul-De-Sacs, Turnarounds & Hammerheads)

Dead end streets may be allowed when deemed appropriate by Engineering and shall meet the following minimum criteria:

1. Dead end roads are allowed on local and private roads only. 
2. Dead end public roads should terminate in a cul-de-sac.  Alternate designs may be considered on a case by case basis depending on topography, length, ADT, or other design constraints. 
3. Dead end streets are allowed only where topography or pre-existing development precludes roadway connections.
4. A roadway ending in a dead end shall be as short as possible, having a maximum length of 400 feet, serving not more than 18 dwelling units.
5. The length of the roadway ending in dead end shall be measured along the centerline of the roadway from the near side right-of-way of the nearest cross street to the farthest point of the dead end right-of-way. 
6. Dead end streets longer than 400 feet may be approved if no other means are available for development of the property and special provisions are made for: public facilities, pedestrian and bicycle circulation and emergency service access and vehicle turnaround.
7. For dead end streets less than one hundred fifty (150) feet in length, sidewalk is required on one side only, but shall include the entire turnaround area.
8. Cul-de-sac bulbs and other approved turnarounds shall have a maximum grade of 5%
9. Cul-de-sacs shall conform to Standard Drawing C300.
10. For alternate termination designs see Standard Drawing C350.

225.3 Opening or Upgrade of Unimproved or Substandard Public Right-Of-Way to Benefit Private Access

An existing unimproved or substandard public right-of-way may be opened, upgraded, or improved for vehicular access subject to a permit.  Requirements include:

1. Applicants for the improvement shall bear all costs inclusive of survey, engineering, construction and maintenance. 
2. Subsequent to this investment, no proprietary rights or exclusive use to the funded improvement will or could be granted within the public right-of-way. 
3. Case-by-case interpretation of construction standards based on the proposed use is necessary to define the extent of construction, location and width of available existing right-of-way consistent with the proposed use or impact.
4. The applicant may be required to dedicate additional right-of-way or easements along the property frontage and at the terminus as deemed necessary by engineering to comply with County standards.
5. If satisfactory access cannot be constructed within the available public right-of-way, the applicant has the option of acquiring additional right-of-way as required or may seek an alternative private access.

225.4 Off-Site Access Standards

On a case by case basis, the County may require construction of improvements within existing off-site (beyond a development site's frontage) public rights-of-way in order to provide adequate safe access to newly created lots or parcels or for other development.  If Engineering determines that off-site roadway improvements are necessary to achieve minimally adequate and safe traffic flow, such improvements may be required before Engineering can recommend approval of a proposed development.

225.5 Structural and Surface Road Improvements Related to Development

1. The County cross section standards of Standard Drawings C110 to C140, community plans in the Comprehensive Plan or design equivalents, shall be applied to the roadway design and constructed in the course of the development or redevelopment along the site frontage and extended to an off-site roadway as established in site specific land use requirements.
2. Road right-of-way or easement width dedications for roadway or public utility purposes along the site frontage (see Section 160.5) is required to meet the adopted cross section width and any additional width identified in a traffic impact analysis.  
3. Frontage improvements shall typically be designed and constructed to the standard cross section. 
4. Staff may rely upon Table 2-3 as a guideline or other alternatives when the full standards cannot be required. 
5. The extent of frontage improvements typically are based on providing a half street improvement.  Occasionally, a situation may call for more than a half street improvement and will be determined based on:
   1. Location of the existing pavement in relation to the right-of-way;
   2. Pavement width;
   3. Pavement condition;
   4. Centered crown, offset crown, shed or other;
   5. Cross slope;
   6. Road grade;
   7. Elevation of existing curbs within 300' of the property lines, including opposite the development.
6. The extent of offsite tapers will be determined per Section 250.6.4 and by the need to:
   1. Match an offset crown;
   2. Match to existing grades and cross slopes
7. When a fee in lieu of improvements ("FILO") is paid, a development's site frontage should meet minimum widths listed in Table 2-3.  When FILO is paid and the minimum frontage improvements are existing, the applicant shall still provide roadway improvements compliant with utility restoration standards of Chapter 7 and Standard Drawings U275 to U290.
    

Table 2-3.  Frontage Improvement Guidelines

Required Frontage Improvements

Type of Development	Inside UGB	Outside UGB
Cell Towers, Solar Facilities	None	None
Partitions, Marijuana subject to land use, Duplexes, Triplexes	Std or  When FILO is paid: Std R/W with Min 16' paved & Min 20' clear roadway	R/W, Min 20' clear roadway
Short Subdivisions (4-10 lots) Adjacent to local/connector	Std	:Std R/W, Min. 20' clear roadway
Short Subdivisions (4-10 lots)Adjacent to local/connector	Std	Adjacent to collector/arterial: Std
Long Subdivisions (11+)	Std	Std
Commercial/Industrial/Institutional/Multi-Family	Std	Std

Std = Dedicate half street right-of-way and construct standard half street cross sections per Section 225.5.a and 225.5.b
Std R/W = Dedicate half street right-of-way per Section 225.5.a and 225.5.b

1. The applicant may be required to provide an analysis of the pavement and base structural sections to determine the structural section and the current condition of the road.  When required, the analysis shall include:
2. Surface Defects
   1. Raveling & Loss of Surface Aggregate
   2. Flushing
3. Surface Deformations (due to a weak sub-base or instability in the pavement)
   1. Rippling and Shoving
   2. Wheel Track Rutting
   3. Distortion
4. Cracking (caused by either thermal stresses or weak base)
   1. Longitudinal Wheel Track Single and Multiple, Alligator
   2. Centerline Single and Multiple, Alligator
   3. Pavement Edge Single and Multiple, Alligator
   4. Transverse Single and Multiple, Alligator
   5. Longitudinal - Meander or Mid-lane
5. The County will review the analysis to determine if an overlay, grind and inlay or full depth reconstruction is warranted based on the existing conditions of the road, the proposed construction impacts and the ADT with the added development.  Different causes of the pavement condition will warrant different remedies.
6. If an existing County or public road terminates along a development's frontage without the benefit of a cul-de-sac or turnaround and the roadway cannot be extended, the development shall construct a full County cul-de-sac per Standard Drawing C300 or approved turnaround per Standard Drawing C350.

225.6 Construction Haul Routes

Construction activities for some developments should not deteriorate roadways classified as local roads, which are more susceptible to damage due to reduced maintenance and/or structural section.  Clackamas County Transportation Maintenance performs annual pavement condition reviews on county maintained roads and may be able to provide a Pavement Condition Index (PCI) rating for the road but not necessarily at the project site frontage.  Temporary construction access via an Entrance Permit may be granted to avoid impacts to local roads. 

Residential subdivisions, commercial, industrial and multifamily developments that utilize a local road as a haul route for construction or will otherwise impact a local road may be required to improve those roads.  If during the work or at the conclusion of work, there is any visible deterioration or drop in PCI of 8 or more the applicant may be required to provide an overlay, grind and inlay or other sufficient improvement to restore the roadway to as good as or better than before the work was initiated.

Should this be required, the applicant shall provide the following:

1. An exhibit depicting haul routes and the location of the construction entrance(s) for all construction equipment and materials if an existing local road will be utilized prior to intersection with a collector or arterial;
2. Such routes may be subject to possible restrictions or conditions to protect existing infrastructure and address traffic impacts;
3. An existing conditions PCI from County Transportation Maintenance, if available;
4. Photographic/video evidence of the conditions before and after construction;
5. Core samples, as requested, of the pavement and base section, before and after construction;
6. A financial surety of not less than $10,000 or 125% of the cost estimate for addressing anticipated infrastructure improvements along the haul route, whichever is greater, prior to Development Permit issuance;
7. Temporary measures to limit further deterioration of the roadways that are currently in poor or very poor condition prior to Development Permit issuance; and/or
8. The applicant shall maintain affected roads at an acceptable and safe level throughout the work.

225.7 Creation of a Private Roadway

In certain circumstances, creation of a private roadway may be the only reasonable method and alternative to provide access to the proposed lots or parcels.  If connectivity and access to adjacent properties is not an issue, private roadways, as addressed in the ZDO, may be permitted.  The following shall apply:

1. Design and construction of a private roadway shall be consistent with the design standards for public roads, except as noted in these Standards regarding widths, cross section and design speed, and in no case shall improvements be less than minimums set out in Standard Drawing R100. 
2. Provisions should be made through a formal maintenance agreement or equivalent to ensure private responsibility for future maintenance.
3. Private roadways and their respective easements shall be distinguished from public roadways and any reservations, restrictions, and maintenance agreements related to the created private roadways shall be described in the land division plat or deed records.
4. The need for utilities and roadway drainage shall be considered.