Traffic Enforcement

The primary goal of the Traffic Enforcement section is to ensure the safety of motorists and pedestrians. The Traffic Enforcement Unit is responsible for keeping Seattle roadways moving during delays, reroutes and collision scenes, civic functions, sporting events, processions, parades and during dignitary visits. 

Motorcycle Unit

The Motorcycle Unit handles:

  • Traffic complaint enforcement
  • High congestion traffic control and enforcement
  • Accident reduction enforcement
  • Dignitary escorts
  • Special event traffic control


Training to become a police motorcycle officer is comprehensive and very difficult. Officers in the Motorcycle Unit must:

  • Successfully complete the Unit's eighty hour Basic Police Motorcycle Operators Course
  • Eight hours of motorcycle recertification training each quarter. 
  • At least one two-day training road trip every three years.
  • Some of our officers are also highly trained to perform in the motorcycle drill team, and perform at public events and parades.

Driving Under the Influence (DUI) Squad

The DUI squad:

  • Detects impaired drivers
  • Responds to collisions
  • Responds to requests by a patrol officer who stops a driver they suspect might be impaired by alcohol and/or other drugs
  • Appear in court frequently, as impaired driving cases are the most litigated misdemeanor crime in the state.

Traffic Collision Investigation Squad (TCIS)

The Traffic Collision Investigation Squad (TCIS) is a detective unit responsible for scene response and investigative follow-up for collisions involving vehicles, bicycles, pedestrians, boats, trains, light rail vehicles, and aircraft in the following circumstances:

  • The death of any person
  • Life-threatening injuries
  • Hit and run collisions where there is a substantial injury
  • Collisions involving substantial bodily injury where it appears a driver was negligent or under the influence of alcohol and or other drugs
  • Vehicular Homicide
  • Vehicular Assault

TCIS also has follow-up investigation responsibility for all other vehicular crimes, including:

  • Felony Eluding
  • Felony Driving Under the Influence 
  • Misdemeanor hit and run collisions

About TCIS Investigations

  • TCIS detectives are available 24/7 to respond to the scene of serious collisions.  
  • On scene, the detectives locate and document scene evidence, take photographs, map the scene with surveying equipment, identify and analyze the various types of tire marks and roadway gouges, and perform vehicle inspections.
  • These tasks often require that all, or at least a portion of the roadway be shut down to traffic while investigators do their work.
  • After the on-scene investigation is complete, the lead detective is responsible for completing the follow-up investigation.  Investigative tasks include obtaining search warrants for evidence, interviewing drivers, victims, and witnesses, obtaining medical records, downloading and analyzing the collision-related electronic data from the involved vehicles, analyzing headlight filaments, processing blood evidence, and more. 
  • Many of the TCIS collision investigations require a mathematical reconstruction be performed in order to determine vehicle speed, direction, momentum, etc.  


Sue Rahr, Interim Chief of Police
Address: 610 5th Avenue, Seattle, WA, 98104-1900
Mailing Address: PO Box 34986, Seattle, WA, 98124-4986
Phone: (206) 625-5011
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The Seattle Police Department (SPD) prevents crime, enforces laws, and supports quality public safety by delivering respectful, professional, and dependable police services. SPD operates within a framework that divides the city into five geographical areas called "precincts".