Traffic Control Requirements

Last Updated: 7-17-2017Print page

Photo of a temporary asphalt ramp being installed for a construction zone.

Creating an Accessible and Safer Work Site 

In general, Seattle’s Standard Specifications contain baseline requirements addressing Safety Rules and Standards, Protection and Restoration of Property, Public Convenience and Safety, Notifications Required of Contractor Activities, Temporary Traffic Control (see Standard Specifications 1-07.1(2), 1-07.16, 1-07.23, 1-07.28, and 1-10), and other General Requirements that may apply to a specific construction. These Standard Specifications may be amended by permit, by the Seattle City Council, or other legal authority for a site or project specific application.

Chapter 49.17 RCW Washington Industrial Safety and Health Act addresses the responsibilities of the employer to ensure safer working conditions. Washington Administrative Code (WAC) Title 296 addresses the responsibilities of the Washington State Department of Labor and Industries as it relates to safer working conditions. WAC Chapter 296-155 addresses most, but not all, construction safety elements typical of construction in the street right-of-way.

Other entities, including regulatory entities, may have additional requirements for safer and accessible work sites. The project applicant shall become familiar with working clearances and other safety requirements as applicable.

It is the responsibility of the contractor to ensure the safety of all persons and the protection of all property.

Photo of a temporary pedestrian walkway beside a construction zone in the street with a barrier between cars and the walkway.

Traffic Control Requirements for In-Street Work

The Traffic Control Manual for In-Street Work is produced and maintained by SDOT’s Transportation Operations Division. It defines the basic principles and standards to be observed by all those who perform work within a street right-of-way so that:

  • Work areas are safer and congestion is minimized;
  • Motorized and non-motorized traffic is warned, controlled and protected;
  • Emergency response is not adversely impacted; and
  • All traffic is expedited through the work zone to the extent possible.

The SDOT Traffic Control Manual is consistent with the standards defined in the Federal Highways Administration’s Manual of Uniform Traffic Control Devices (MUTCD), including the following:

  • Required components of a traffic control plan;
  • The circumstances under which a traffic control plan is required as a permit condition for work that takes place in or adjacent to the street right-of-way;
  • The appropriate type and location of traffic control devices;
  • Procedures for obtaining permission to work in the street right-of-way;
  • Requirements for pedestrian access, control and protection;
  • Requirements for curb space management including loading, transit and special parking;
  • Detours and street closures;
  • Emergency work;
  • Constraints on time of construction to accommodate time of day and special event traffic volumes; and
  • Standard barricades and signing illustrations.

SDOT requires a traffic control plan be submitted for review and approval prior to the commencement of work in the public right-of-way when:

  • The project will impact pedestrian, bicycle or vehicle movements on an arterial street; or
  • The project will impact pedestrian, bicycle or vehicle movements in a high impact area as defined by the City Traffic Engineer;
  • Traffic control cannot be made to match exactly sketches within the City of Seattle Traffic Control Manual for In Street Work (Traffic Control Manual); or
  • Other special circumstances exist as determined by the City Traffic Engineer.

When working near King County Metro facilities (trolley wires, bus stops, etc.) the Permittee must also coordinate with King County Metro. Metro can be contacted at or 206-477-1140. Additional information regarding King County Metro requirements can be found in the Traffic Control Manual: Permission to Work

Additional information regarding traffic control plans can be found in CAM 2110, CAM 2111, and CAM 2112.