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Transportation

Road Services - Service levels for unincorporated-area roads

Work on roads in unincorporated King County is guided by a tier system that categorizes roads in part by how much traffic is on the road. The over 1,500 miles of roadway that Road Services is responsible for has been ranked into one of five tiers. Tier 1 roads will receive the most service, while Tier 5 roads will receive the least. The criteria used to make tier assignments includes traffic volume, projected lengths of detours, and whether the road provides sole access, is a lifeline route, or is important for transit or freight.

The tiered system focuses resources and guides decisions about where and in what order work will be provided. It also directs budget programming, workforce planning, and deployment decisions to protect roads that serve the most users.

About the tiered service levels

Tier 1 — Consistently reliable access
Tier 1 roads carry 50% of the County Road System’s total daily trips.

Features: Heavily traveled; connect large communities, major services, and critical infrastructure.

Service: Will receive the highest level of storm response, including the first roads to receive snow removal. Users of Tier 1 roads should expect good road and bridge condition and well-maintained drainage. These roads will receive the highest level of maintenance and preservation.

 

Tier 1 roads slideshow
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Tier 2 — Generally reliable access
Tier 2 roads carry 20% of the County Road System’s total daily trips.

Features: Heavily traveled roads that serve smaller geographic areas; provide alternate routes to Tier 1 roads.

Service: Will receive a lower level of storm and snow response. Will receive maintenance to keep them in good condition. In general, preservation efforts will be more reactive and prioritized based on level of risk and availability of funding.

Tier 2 roads slideshow
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Tier 3 — Somewhat reliable access
Tier 3 roads carry 15% of the County Road System's total daily trips.

Features: Highly used local roads that serve local communities and large residential areas.

Service: Will receive little to no storm and snow response, especially during significant storms. Maintenance and preservation will focus on slowing deterioration, but users should expect to see wear and tear to roadways, possible load limits, lower posted speed limits, and long-term partial closures.

Tier 3 roads slideshow
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Tier 4 — Less reliable access
Tier 4 roads carry 5% of the County Road System's total daily trips.

Features: Local residential dead-end roads with no other outlet.

Service: Will receive virtually no storm and snow response. Maintenance will be limited to activities that preserve access. Users may expect to see a number of one-lane roads with some downgraded to a gravel surface, depending on the level of deterioration and availability of funding.

Tier 4 roads slideshow
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Tier 5 — Least reliable access
Tier 5 roads carry 10% of the County road system's total daily trips.

Features: Local residential roads that have alternative routes available for travel in case of road closures.

Service: Will receive virtually no storm and snow response. Maintenance will be limited and based on factors such as life safety and risk, resulting in a growing number of deteriorating roads. Users can expect to see some closures, which may result in longer detours and difficulty accessing property. These roads may also be downgraded to a gravel surface, restricted to one lane, and have load limits and lower speed limits.

Tier 5 roads slideshow
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Contact us

We encourage you to contact us if you have questions or comments about the tiered service level system.

  • Call us at 206-477-3528
  • Send us an email

Information from the Road Services Division's website is available to people with disabilities in alternate formats upon request by calling 206-477-3839 or 711 for the TTY relay service.

External link = External link

Also see

Tiered service levels map
Tiered service levels map
Roads' future

Snow and ice

Snow and ice: This year is different

Contact us

We encourage you to contact us if you have questions or comments about the tiered service level system.

• Call us at 206-477-3528
• Send us an email