Traffic Mitigation & Concurrency (UDC Chapter 30.66B SCC)

• Overview and Background
• Chapter 30.66B SCC (select The Unified Development Code and then Chapter 30.66B)
• Currently Adopted Public Works Rules for Chapter 30.66B SCC
• Ultimate Capacity
• Impact Mitigation Fee Credit

  Reciprocal Traffic Mitigation Agreements, Forms & Information

Traffic Study Tools & Information for Developers & Traffic Consultants

• Turn Lane Channelization Analysis Guidelines (November 2014)
  • Left Turn Lane Channelization Analysis shall be completed using the Guidelines for Left–Turn Lanes from the ITE 1990 Compendium of Technical Papers (PDF). (November 2014)
  • Right Turn Lane Channelization Analysis shall be completed using the Right-Turn Lane Guidelines found in section 1310.04(3) and Exhibit 1310-11 of the WSDOT Design Manual. (November 2014)
• Arterial Unit Categories (PDF) (October 2015)
• Inadequate Road Condition Designations (PDF) (September 2021)
• Key Intersections List (PDF) (June 2022)
• Map - Key Intersections (PDF) (June 2022)
• Map - Arterial Units (PDF) (December 2021)
• Map - Arterial Units Status (PDF) (December 2021)
• Required Format for Trip Distributions (PDF) (May 2017)
• State Highways of Statewide Significance as Designated by WSDOT (PDF)
• Synchro Calibration Revision (PDF)
• Requirements for Traffic Studies with Future Level-of-Service Analysis (PDF) (January 2017)

Annual Concurrency Reports

• Overview of the Concurrency Management System (PDF)
• 2017 Report (PDF) (April 1, 2016 through March 31, 2017)
• 2017 Report (PDF) (January 1, 2017 through December 31, 2017)
• 2018 Report (PDF)
• 2019 Report (PDF)
• 2020 Report (PDF)
• 2021 Report (PDF)