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The Clackamas County Roadway Standards (hereafter referred to as the "Standards") provides a handbook for both roadway design and construction of public and private roadway improvements, alteration of drainage on private property in the unincorporated areas and outside of a storm water district and site design standards for required site improvements related to land use approvals. The purpose of these Standards is:
- To provide specific, consistent and acceptable road design and construction elements for applicants, developers and other private parties constructing or modifying road right-of-way facilities or on-site improvements which require County permits.
- To establish uniform criteria that still provide context sensitive flexibility in guiding the County's design and construction of County facilities.
- To allow for practical approaches to road design and construction challenges that provide the best fit solution given the realities of financial constraints and community context.
Roadway designs in Clackamas County strive to achieve sustainable outcomes when safety, convenience, aesthetics, resource protection, ease of maintenance, and community livability are considered.
These Standards provide the minimum criteria for design and construction of roadways, accesses, site development, and integrated drainage facilities under the jurisdiction of Clackamas County.
It is not the objective of this handbook to limit the creative efforts of Engineers in providing alternate solutions to specific problem areas or relieve the responsibility for professional engineering judgment. Practical designs that preserve the function and safety of the roadway system and promote sustainability by offering benefits to aesthetics, resource protection, ease of maintenance, and livability are encouraged.
Dan Johnson, Director
Clackamas County Department of Transportation and Development
June 1, 2020
Definitions
- ADA: Americans with Disabilities Act of 1990.
- ADA standards: Requirements and standards resulting from the Americans with Disabilities Act of 1990 and adopted by Clackamas County as standards for accessible design within Clackamas County rights-of-way.
- Alteration: A change to a facility that affects or could affect pedestrian access, circulation, or use. Alterations include, but are not limited to, resurfacing, rehabilitation, reconstruction, historic restoration, or changes or rearrangement of structural parts or elements of a facility.
- Applicant: Property owner or person designated by the property owner to be the representative for an application for a development proposal, permit or approval, or their successors or assigns. As this pertains to utilities, see County Code Section 7.03.020.
- Average daily traffic ("ADT"): The number of vehicles traveling in both directions over a given time period greater than one day but less than one year, divided by the number of days in that time period. Commonly, traffic counts completed at various times of year are adjusted for time of year to account for seasonal and day of week variations. For the purposes of determining whether a roadway is "very low volume", ADT's shall be based upon a 20 year projected ADT.
- Backfill: Replacement of excavated material with suitable material compacted as specified.
- Blended transition: A connection between the pedestrian access route at the level of the sidewalk or pedestrian path and the level of the pedestrian street crossing that has grade in the direction of pedestrian travel of 5 percent or less.
- Breakaway: A structure that is designed to yield when impacted by a vehicle and has been tested and found acceptable in accordance with NCHRP Report 350.
- Clear zone: See County Code Section 7.03.020.
- Clackamas County ("County"): The political subdivision of the State of Oregon providing statutory authority administered through its Board of County Commissioners ("BCC").
- Commercial: Shall include industrial, multi-family and institutional development.
- Compaction: The densification of a fill by mechanical means.
- County: See "Clackamas County".
- County Road Official: See County Code Section 7.03.020.
- County Surveyor: See ORS 209.005 (2).
- Cross slope: The slope perpendicular to travel of a road or pedestrian facility.
- Crosswalk: Under ORS 810.220 a crosswalk is a legally defined area for pedestrian crossing of the surface of a roadway and may be marked or unmarked.
- Cul-de-sac: A short street having one end open to traffic and the other temporarily or permanently terminated by a vehicle turnaround at or near the terminus.
- Curb ramp: A ramp that cut through or is built up to the curb. Curb ramps can be perpendicular or parallel to the curb or a combination of parallel and perpendicular ramps.
- Dead end: A road without an exit.
- Dedication: The designation and gift of land by its owner. In the context of this document, it is the perpetual easement for right-of-way purposes to the public.
- Design speed: The speed approved for the geometric and roadside design of the physical features of a road.
- Developer: See "Applicant."
- Development Permit: A permit issued to address major work or activities in a right-of-way under the jurisdiction of Clackamas County and/or to address improvements on private property that are required as part of land use.
- Ditch: An excavation dug in the earth used to convey water.
- Drainage facilities: The physical elements used to convey, absorb, or store runoff such as pipes or channels, and detention or retention ponds or bio-swales.
- Driveway ("entry", "entrance", or "access"): A private road on private property that is maintained with private funds.
- Driveway, shared access: A road which is on private property in an easement and which is maintained with private funds, generally considered to provide practical and legal access to multiple properties.
- Easement: See ZDO.
- Engineer: A Professional Engineer with Civil Engineering expertise holding a valid license from the State of Oregon.
- Engineering: The County Department of Transportation and Development ("DTD") office of Engineering formed by the Board of Commissioners and administrating the DTD ordinances and related issues within unincorporated Clackamas County.
- Engineering Geologist: A registered Professional Geologist holding a valid license from the State of Oregon.
- Entrance Permit (aka "Entry Permit", "Driveway Permit"): See "Entry Permit" of County Code Section 7.03.020.
- Fixed object: See County Code Section 7.03.020.
- Frontage improvements: Required improvements along an applicant's property frontage.
- Functional classification: The hierarchy of roadways in descending order of mobility, traffic volume and design speed, and ascending order of access: Freeway/Expressway, Major Arterial, Minor Arterial, Collector, Connector, and Local. Functional classifications of individual roadways can be found on Maps V-2a and V2-b of the Clackamas County Comprehensive Plan. Descriptions of each functional classification can be found on Table V-2 and Table V-3 of the Comprehensive Plan.
- Grade: See ZDO.
- Grade break: The line where two surface planes with different grades meet.
- Intersection: The point where a public roadway or private roadway intersects with a public roadway, private roadway or driveway.
- Intersection sight distance ("ISD"): The distance that a motorist can see approaching traffic when entering or exiting a roadway at an intersection.
- Landing: A generally flat road or driveway approach to any public or private road. Also, the generally flat area at the back of the sidewalk ramp, typically four feet wide for sidewalk ramps.
- Landscape screening: Plantings, shrubbery, bushes or other foliage intended to screen the base of a wireless telecommunication facility from public view.
- Land Surveyor: A Professional Land Surveyor holding a valid license from the State of Oregon.
- Low impact development (LID): An innovative ecosystem based approach to storm water management that results in fewer environmental impacts.
- Pedestrian access route: A prepared surface provided for pedestrian travel within the public right-of-way, including sidewalks and multiuse paths.
- PROWAG: Public Right-of-Way Accessibility Guidance as set forth under Section 1190.1 of the Americans with Disabilities Act of 1990 and adopted by federal agencies for implementing the Americans with Disabilities Act of 1990, Section 504 of the Rehabilitation Act and the Architectural Barriers Act.
- Public utility: See ZDO.
- Public utility easement ("PUE"): An easement for the use of a Public Utility. The use of the PUE shall include telecommunications as per ORS 758.035.
- Ramp slope: The grade of a curb ramp parallel to the direction of pedestrian travel.
- Recoverable slope: A slope on which the driver of an errant vehicle can regain control of the vehicle. Slopes of 4H:1V or flatter in the foreslope and 3:1 in the backslope are considered recoverable.
- Right-of-way ("ROW"): See ZDO.
- Right-of-Way Permit: A permit issued to address minor work or activities in a right-of-way under the jurisdiction of Clackamas County.
- Road: See ZDO.
- Road, county: See ZDO.
- Road, private: See ZDO.
- Road, public: See ZDO.
- Roadway: See ZDO.
- Road Official: See County Road Official
- Running slope: The grade of a Pedestrian Access Route that is parallel to the direction of pedestrian travel. In reference to a curb ramp the term Ramp Slope is also used.
- Rural: Those unincorporated County areas outside the current designated Urban Growth Boundary (UGB).
- Shoulder: The paved or compacted graveled portion of the roadway outside the traveled portion of the roadway that is available for emergency parking or non-motorized use.
- Sidewalk: See ZDO.
- Stopping sight distance ("SSD"): The minimum sight distance available on a roadway to enable a vehicle traveling at or near the design speed to stop before reaching a stationary object in its path.
- Storm drainage system: A means to control storm water through natural or constructed elements by conveyance, absorption, or storage.
- Street: See ZDO.
- Temporary: Lasting for a limited time.
- Traffic Engineer: A Professional Engineer with traffic engineering expertise or a Professional Traffic Engineer holding a valid license from the State of Oregon.
- Traveled portion of the roadway: See County Code Section 7.03.020.
- Trip generation: The number of vehicle trips generated by a particular land use.
- Urban: Those areas within the current designated Urban Growth Boundary ("UGB") as designated by Metro.
- Utilities: Any water, gas, sanitary or storm sewer, electrical, telephone, drainage way, wire, or television communication service and all persons, companies, districts or governmental agencies supplying the same.
- Utility Permit: See County Code Section 7.03.020
- Very low volume: A roadway with a 20 year projected volume of 400 ADT or less or an intersection with a 20 year projected entering volume of 400 ADT or less.
Abbreviations
- AASHTO: American Association of State Highway and Transportation Officials
- ADA: Americans with Disabilities Act
- ADT: Average daily traffic
- APWA: American Public Works Association
- ASTM: American Society for Testing and Materials
- BCC: Clackamas County Board of County Commissioners
- CRC: Clackamas Regional Center
- DTD: Clackamas County Department of Transportation and Development
- EOR: Engineer of Record
- FHWA: Federal Highway Administration
- ISD: Intersection sight distance
- ITE: Institute of Transportation Engineers
- MPH: Miles per hour
- MUTCD: Manual on Uniform Traffic Control Devices
- ODOT: Oregon Department of Transportation
- PI: Point of intersection
- PC: Point of curvature
- PT: Point of tangency
- SSD: Stopping sight distance
- UGB: Urban Growth Boundary
