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Traffic Engineering

image of traffic signals

Sonoma County Public Infrastructure manages the engineering, construction, and maintenance of streetlights, signs, traffic signals, pavement markings, and other devices that regulate traffic and improve roadway safety.

Our Traffic Engineering team works to ensure County roads are designed and operated for maximum safety and efficiency. All traffic control devices are installed and maintained by trained professionals and must meet state standards.

What We Do

  • Maintain and operate traffic control devices (signals, signs, striping, and lights)
  • Set and review speed limits and other roadway regulations
  • Conduct traffic surveys and safety studies
  • Implement traffic calming measures, like speed humps
  • Oversee crosswalks, parking restrictions, and signage
  • Support community programs, such as Adopt-a-Road and roadside clean-up

Learn More


Traffic Control Devices

Traffic control devices include signs, signals, and pavement markings that guide drivers and pedestrians. Placement is determined by County engineers following strict safety and operational standards.

For statewide design requirements, see the California Manual for Uniform Traffic Control Devices (MUTCD).

Traffic Impact Study Guidelines

Developers and planners must conduct traffic impact studies in line with County standards.
Traffic Impact Study Guidelines (PDF)