Transportation Engineering

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.

Definitions | Abbreviations | Associated Documents | ADA (Americans with Disabilities Act) Checklists

Standards

Chapter 1 - General Considerations

Section 110 - General Provisions

Section 115 – Other Standards, Guidelines & References

Section 120 - Development Related Improvements

Section 130 - Permit Requirements

• 130.1 General Requirements
• 130.2 Exceptions To Requirements For Permit
• 130.3 General Permit Requirements
• 130.3.1 Responsibility
• 130.3.2 Application Submission
• 130.3.3 Fees
• 130.3.4 Contractor Requirements For Licensing, Bonding, & Insurance
• 130.3.5 Property Owner Requirements For Insurance
• 130.3.6 Permit Approval
• 130.3.7 Application Period, Approval Period & Extensions
• 130.3.8 Revocation Or Modification Of Permits
• 130.3.9 Notification
• 130.3.10 Construction Noise
• 130.3.11 Inspection
• 130.3.12 Final Inspection/Project Close-Out
• 130.4 Permit Types & Requirements; Stormwater & Erosion Control Reviews
• 130.4.1 Development Permit
• 130.4.2 Entrance (Entry) Permit
• 130.4.3 Utility Placement Permit
• 130.4.4 Right-Of-Way Permit
• 130.4.5 Stormwater Review
• 130.4.6 Erosion Control Review

Section 140 – Permit And Plan Submittal Requirements 

• 140.1 Development Permit Submittal
• 140.1.1 Plan View Sheets
• 140.1.2 Profile View
• 140.1.3 Half Street/Cross Section Views
• 140.1.4 Stormwater Report & Drainage Calculations
• 140.1.5 Other Requirements
• 140.1.6 Other Reviewing Agencies
• 140.1.7 As-Built Plans
• 140.2 Entrance, Utility And Right-Of-Way Permit Submittals

Section 150 - Surveying 

• 150.1 General
• 150.2 Existing Survey Monuments
• 150.3 New Survey Monuments

Section 160 - Dedication Of Public Right-Of-Way And Easements 

• 160.1 Requirement For Public Easement
• 160.2 County Approval Required
• 160.3 Development Permit Required
• 160.4 Minimum Width Requirements For Rights-Of-Way And Easements
• 160.5 Public Easement Dedication Process
• 160.6 Dedication Of Public Right-Of-Way And Easements On The Plat
• 160.7 Dedication Of Public Right-Of-Way And Easements Outside Of The Plat

Section 170 - Design Modifications & Ada Exceptions 

• 170.1 Design Modifications
• 170.1.1 Modification Request Submittal
• 170.1.2 Criteria For Modification Of Standards
• 170.1.3 Review
• 170.1.4 Appeal
• 170.2 Ada Exceptions
• 170.2.1 Exceptions For New Ada Accessibility Features
• 170.2.2 Exceptions For Alterations To Existing Ada Accessibility Features
• 170.2.3 Ada Exception Request Submittal

Section 180 - Construction Inspection 31 

• 180.1 General
• 180.2 County Inspector Authority And Duties
• 180.3 Primary Inspector
• 180.3.1 Developer Engineer Agreement
• 180.3.2 Certificate Of Compliance And Completion
• 180.3.3 When A Primary Inspector Is Required
• 180.3.4 Primary Inspector Authority And Duties
• 180.4 Testing
• 180.5 Required Inspections Of Ada Accessibility Features
• 180.6 Inspection Requests
• 180.7 Failure To Obtain Inspection

Section 190 - Performance Surety, Warranty And Acceptance Of Work 34 

• 190.1 General
• 190.2 Substantial Completion For Development Permits
• 190.3 Performance Surety
• 190.3.1 Forms
• 190.3.2 Timeframe
• 190.3.3 Amount
• 190.4 Maintenance And Warranty Period For Development Permits
• 190.5 Maintenance And Warranty Period For Utility Permits
• 190.6 Acceptance Of Work
• 190.7 Acceptance Of Roads
• 190.8 Nonperformance Of Permit

Chapter 2 - Roadway Design & Construction

Section 210 – General

Section 215 - Functional Classification & Regional Street Design Guidelines

Section 220 - Access Management 

• 220.1 General
• 220.2 General Requirements
• 220.3 Access Spacing Standards
• 220.4 Additional Access Requirements
• 220.5 Roadway Intersection Management
• 220.6 Modification Considerations

Section 225 - Roadway Development 

• 225.1 Future Extension Of Roadways Related To Development
• 225.2 Termination Of Roadways/Dead End Streets (Cul-De-Sacs, Turnarounds & Hammerheads)
• 225.3 Opening Or Upgrade Of Unimproved Or Substandard Public Right-Of-Way To Benefit Private Access
• 225.4 Off-Site Access Standards
• 225.5 Structural And Surface Road Improvements Related To Development
• 225.6 Construction Haul Routes
• 225.7 Creation Of A Private Roadway

Section 230 – Residential, Agricultural & Logging Driveway Design 

• 230.1 General
• 230.2 Standard Drawings
• 230.3 Provisions For Ada Accessibility Of Driveways
• 230.4 Driveway Vertical Geometry
• 230.5 Driveway Horizontal Geometry
• 230.6 Driveway Structural Capacity
• 230.7 Emergency Services
• 230.8 Driveway Surface Water
• 230.9 Driveway Culverts
• 230.10 Intersection Angle
• 230.11 Permit Requirements
• 230.12 Inspection Requirements
• 230.13 Intersection Sight Distance Requirements
• 230.14 Maintenance Requirements

Section 240 - Sight Distance 

• 240.1 General
• 240.2 Sight Distance – Standard
• 240.3 Existing Offsite Public Roadway Intersections
• 240.4 Intersection Sight Distance Measurement
• 240.5 Stopping Sight Distance Measurement
• 240.6 Sight Distance Design Speed

Section 245 - Roadside & Clear Zone 

• 245.1 General
• 245.2 Clear Zone Measurement
• 245.3 Clear Zone Standards
• 245.4 Clear Zone Requirements
• 245.4.1 Fixed Objects Allowed In Clear Zone
• 245.4.2 Embankments And Ditches
• 245.4.3 Vegetation
• 245.4.4 Above Ground Appurtenances
• 245.5 Clear Zone Exceptions

Section 250 - Geometric Design 

• 250.1 General
• 250.1.1 Roadway Cross Section
• 250.1.2 Design Speed
• 250.1.3 Design & Control Vehicle
• 250.2 Curbs
• 250.3 Pedestrian Improvements - General
• 250.3.1 Sidewalks
• 250.3.2 Shared-Use (Multi-Use) Paths
• 250.3.3 Cycle Tracks
• 250.3.4 Landscape Strips
• 250.3.5 Right-Of-Way And Easements
• 250.3.6 Horizontal And Vertical Clearance
• 250.3.7 Pedestrian Facilities Cross Slope
• 250.3.8 Curb Ramps
• 250.3.9 Curb Ramp Closures
• 250.3.10 Bulb Outs (Curb Extensions)
• 250.3.11 Midblock Crosswalks
• 250.3.12 Pedestrian Facility Condition & Repair
• 250.4 Bicycle Improvements
• 250.4.1 Shared Use Paths
• 250.4.2 Other Bicycle Facilities
• 250.5 Transit Improvements
• 250.6 Horizontal Alignment
• 250.6.1 Horizontal Curves
• 250.6.2 Design Intent For Horizontal Curves
• 250.6.3 Exceptions For Very Low Volume (≤400 Adt) Local Streets With A Speed Of 25 Mph Or Less
• 250.6.4 Roadway And Marking Transitions
• 250.6.5 Lane Widths
• 250.7 Vertical Alignment
• 250.7.1 Minimum Roadway Gradient
• 250.7.2 Maximum Roadway Gradient
• 250.7.3 Intersection Landing
• 250.7.4 Vertical Curves
• 250.7.5 Roadway Widening
• 250.7.6 Superelevation
• 250.8 Intersections
• 250.8.1 Minimum Curb Radii
• 250.8.2 Intersection Angle
• 250.8.3 Roadway/Lane Offset
• 250.8.4 Tangent Section
• 250.8.5 Residential Intersection Design
• 250.8.6 Roundabouts
• 250.8.7 Intersection Sight Distance
• 250.8.8 Turn Lane Design
• 250.9 Roadway Grading
• 250.10 Non-Traversable Medians And Accessible Route Islands 63

Section 252 - Structural Section 

• 252.1 Subgrade Evaluation
• 252.2 Asphaltic Concrete
• 252.3 Portland Cement Concrete ("PCC")
• 252.4 Cement Stabilized Roadway (CSR) By Full Depth Reclamation (FDR) Or Cement Treated Base (CTB)
• 252.4.1 General
• 252.4.2 Materials, Preparation & Equipment
• 252.4.3 Construction
• 252.4.4 Curing
• 252.4.5 Micro-Cracking
• 252.4.6 Performance
• 252.4.7 Traffic Control Considerations

Section 255 - Landscaping 

• 255.1 Topsoil
• 255.2 Shrubs, Plants And Grasses
• 255.3 Street Trees
• 255.3.1 Street Tree Selection
• 255.3.2 Street Tree Quality At Time Of Planting
• 255.3.3 Street Tree Condition At Time Of Planting
• 255.3.4 Preparation Of Tree Planting Holes
• 255.3.5 Seating Of Trees
• 255.3.6 Staking
• 255.3.7 Establishment Period
• 255.3.8 Root Barrier
• 255.4 Sight Distance

Section 260 - Traffic Signals, Flashers & Communication 

• 260.1 Traffic Signal Approval
• 260.1.1 Traffic Analysis
• 260.1.2 Traffic Signal Warrants
• 260.1.3 Traffic Signal Spacing
• 260.2 Traffic Signal Design
• 260.3 Traffic Signal Materials
• 260.4 Material Submittals
• 260.5 Traffic Signal Funding And Agreements
• 260.6 Underground Communication Conduit
• 260.7 Fiber Optic Communication
• 260.8 Flashers In School Zones

Section 265 - Traffic Calming

Section 270 - Traffic Signing 

• 270.1 Design And Construction Requirements
• 270.2 Street Name Signs
• 270.3 End Of Street
• 270.4 End Of Sidewalk
• 270.5 Sign Mounting

Section 280 - Pavement Markings 

• 280.1 Crosswalk Markings
• 280.2 Left Turn And Right Turn Lanes Markings
• 280.3 Stop Bars
• 280.4 Transverse Marking Materials
• 280.5 Longitudinal Markings
• 280.6 Reflective Pavement Markers (RPMS)
• 280.7 Temporary Markings
• 280.8 Marking Materials
• 280.9 Marking Layout

Section 290 - Temporary Traffic Control 

• 290.1 General
• 290.2 Control Of Site
• 290.3 Temporary Pedestrian Accessible Route
• 290.4 Impacts To Traffic Signals
• 290.5 Temporary Road Closures

Section 295 - Transportation Impact Study (TIS) Requirements 

• 295.1 General
• 295.2 Requirement For A Traffic Impact Study
• 295.3 Traffic Study Scope And Coordination
• 295.4 Traffic Engineering Expertise
• 295.5 Coordination With Other Agencies
• 295.6 Zone Changes And Comprehensive Plan Amendments
• 295.7 Clackamas Regional Center (Crc) Area Analysis Period
• 295.8 Analysis Methodology
• 295.8.1 Two-Way Stop Controlled (Twsc) Intersections
• 295.8.2 All-Way Stop Controlled (Awsc) Intersections
• 295.8.3 Signalized Intersections
• 295.8.4 Roundabout Intersections
• 295.9 Signalized Intersection Analysis Parameters
• 295.10 Peak Hour Factor ("Phf")
• 295.11 Microsimulation Models
• 295.12 Growth Rates And In Process Traffic
• 295.13 Turning Movement Counts
• 295.13.1 Count Hours
• 295.13.2 Day Of Week
• 295.13.3 Holidays
• 295.13.4 Current Counts
• 295.13.5 Vehicle Classification, Bicycles And Pedestrian Data
• 295.14 Trip Generation
• 295.15 Trip Distribution
• 295.16 Queuing Analysis
• 295.17 Traffic Safety
• 295.17.1 Crash History
• 295.17.2 Truck Circulation
• 295.18 Mitigation
• 295.18.1 Turn Lane Warrants
• 295.18.2 Traffic Signal Approval
• 295.18.3 Analysis Of Impacts On Local, Residential Streets
• 295.18.4 Other Mitigation
• 295.19 Traffic Study Components
• 295.19.1 Executive Summary
• 295.19.2 Project And Study Area Description
• 295.19.3 Analysis Periods And Scope
• 295.20 Submittal Requirements

Chapter 3 - On Site Design Of Commercial, Industrial And Multifamily Developments

Section 310 - General

Section 320 – Parking Areas 

• 320.1 Maximum Slopes And Grades
• 320.2 Pedestrian Walkways
• 320.3 Vehicular Circulation And Maneuvering
• 320.4 Parking And Maneuvering Area Surface & Structural Section
• 320.5 Parking Stalls
• 320.6 Curbs And Wheel Stops
• 320.7 Signage And Pavement Markings
• 320.8 Reciprocal Access Easements

Section 330 - Commercial, Industrial And Multifamily Driveways

Section 340 - Refuse And Recycling Enclosure Standards For Commercial, Industrial And Multifamily Developments

Chapter 4 - Storm Water Management

Section 410 - General 

• 410.1 Regulatory Authority
• 410.2 Engineering Regulations
• 410.3 Erosion Control Contractor Certification Not Required
• 410.4 Fees

Section 420 - Exceptions To Wes Standards 

• 420.1 Best Management Practices (Bmp) & Low Impact Development Approaches (Lida)
• 420.2 Acreage As A Bmp
• 420.3 Surface Water Management Applicability
• 420.4 Underground Injection Control (Uic) Devices

Section 430 - Hydrology 

• 430.1 Acceptable Hydrology Methods (Detention Hydraulics)
• 430.2 Rational Method
• 430.2.1 Rational Method Basic Methodology
• 430.2.2 Runoff Coefficient
• 430.2.3 Rainfall Intensity
• 430.2.4 Time Of Concentration
• 430.2.5 Design Storm
• 430.2.6 Drainage Area

Section 440 - Storm Drainage Components

• 440.1 Pipes And Culverts
• 440.1.1 Pipe Material
• 440.1.2 Pipe Size
• 440.1.3 Pipe Slope
• 440.1.4 Pipe Cover
• 440.1.5 Pipe Alignment And Connections
• 440.1.6 Pipe Inspection Including Televiewing
• 440.2 Catch Basins And Inlets
• 440.2.1 Catch Basin Type
• 440.2.2 Catch Basin And Inlet Spacing And Location
• 440.2.3 Catch Basin And Inlet Connections
• 440.2.4 Lateral Connections
• 440.3 Manhole Sizing And Alignment
• 440.4 Open Channels And Ditches
• 440.4.1 Natural Channels
• 440.4.2 Constructed Channels & Ditches
• 440.4.3 Design Criteria

Section 450 - Detention And Downstream Impacts

Section 460 - Water Quality

Section 470 - Erosion And Sedimentation Control

Chapter 5 - Structures

Chapter 6 - Street Illumination

Section 610 - General 

• 610.1 Street Illumination Required Within UGB
• 610.2 Street Illumination Design By Pge
• 610.3 Street Illumination Are Option A
• 610.4 Illuminating Engineering Society (IES)
• 610.5 Fixture Approval

Section 615 - Process For Obtaining Approval For Street Illumination 

• 615.1 Approval Process
• 615.2 Construction & Installation
• 615.3 Rates

Chapter 7 - Utilities

Section 710 – General 

• 710.1 Potholing Requirements
• 710.2 Location Requirements
• 710.3 Pedestrian Considerations
• 710.4 Structures
• 710.5 Pressurized Pipes
• 710.6 Vertical Clearance
• 710.7 Burial Requirements
• 710.7.1 Depth
• 710.7.2 Warning Signage & Ability To Locate
• 710.7.3 Pedestal Placement
• 710.8 Requirements And Specifications For Trench Backfill
• 710.9 Open Cuts Of Paved Roadway Surfaces
• 710.10 Concrete Street Surface Repairs

715 Small Wireless Facilities 

• 715.1 Application
• 715.2 Review And Approval Period
• 715.3 Location Requirement
• 715.4 Other Siting Requirements
• 715.5 Access Requirements
• 715.6 Aesthetics
• 715.7 Abandonment And Removal
• 715.8 Clackamas Regional Center Design Plan Area Requirements
• 715.9 Inspection
• 715.10 Expiration
• 715.11 Radio Frequency (Rf) Certification Report

Associated Documents

• Certificate of Compliance and Completion
• Clackamas County Street Tree List
• Developer - Engineer Agreement
• Design Modification form
• Entrance Permit Matrix
• Shrub, Groundcover, Riparian Plant List 

ADA (Americans with Disabilities Act) Checklists

• ADA Facility Exception Request Form
• Medians/Traffic Islands
• Crosswalks and Traffic Signals
• Sidewalk or Multiuse Path
• Curb Ramps

Our goal is to eliminate serious crashes and deaths on our roads take careful planning. As our needs and technology evolve, new safety solutions emerge. Come join us on our ride to update our comprehensive transportation safety plan and programs!

Updating our safety plan will:

• Review existing practices and procedures for post-crash care within Clackamas County.
• Identify trends, assess data, and provide recommendations to ultimately eliminate severe crashes in Clackamas County.
• Evaluate program readiness to deliver the Safe Systems approach in transportation safety adoption and develop an implementation plan.
• Develop a list of priority challenges and potential solutions.
• Revise the 2019 Transportation Safety Action Plan.

Who We're Working With

Creating a culture of safety involves us all. A baseline of safety allows each one of us to be productive and meaningful members of our communities. As the authority for Clackamas County roads, the county is leading a collaborative effort with our local jurisdictions and community partners to identify and address traffic safety concerns, and to develop evidence-based solutions to continue to improve safety.

After our focus groups and community feedback, we will develop a list of recommendations for the Department of Transportation and Development to consider in the Transportation Safety Action Plan update. We have invited many partners to help us. The following have attended an initial kickoff meeting or participated in other ways:

• Clackamas Fire
• Clackamas County Walk Bike Committee
• Federal Highway Administration
• City of Lake Oswego
• City of Gladstone
• City of Canby Traffic Safety Committee
• Oregon Department of Transportation
• Oregon Metro Government
• City of Milwaukie
• OHSU School of Public Health
• US Dept of Veteran Affairs
• Clackamas Traffic Safety Commission
• The Street Trust

Please contact the project manager, Rob Sadowsky, at rsadowsky@clackamas.us if you are interested in participating in future meetings.

Timeline

The planning work will be completed between January 2025 and December 2026. There are four distinct components to the planning project as follows:

2025 – 2026 Project Timeline

Community Engagement
Objective: Support the development of a toolkit and guidebook to integrate best practices around community engagement into transportation planning throughout the county.

Triage
Objective: Strengthen the post-crash care element of the safe system approach in Clackamas County through the development of a Post-Crash Evaluation and Trauma Support Framework

Safe Systems Readiness Services
Objective: Evaluate the county's readiness for Safe Systems Approach adoption and develop a roadmap for actions needed to achieve full adoption of the approach.

Update the Transportation Safety Action Plan
Objective: Integrate the safe systems approach, lessons from the triage research and community engagement framework and update Transportation Safety Action Plan. This will include reanalyzing traffic crash data and identifying new safety projects and strategies.

Each of these projects will also produce guidance for local entities to adopt their own set of policies and systems for transportation safety.

Collaborate. Review. Implement.

Community members and technical experts will have opportunities to provide feedback on specific project elements at periodic public meetings. Meetings are open to the public and include time for public comments. No meetings are scheduled at this time.

Additional Resources