This page delivers traffic analytics for King County, Washington. Our metrics are calculated with multi-sourced, cross-verified data from real-world mobile and sensor networks, and averaged for King County, Washington among 2,742 road miles divided in 110,695 segments. Our metrics go beyond simple volume counts to provide actionable insights on traffic intensity, congestion, commercial vehicle flow, and network performance with highest possible granularity (average segment length is 131 ft). Whether you are evaluating a new retail location, planning logistics routes, or assessing infrastructure needs, this data helps you move from assumptions to certainty.
Data sourced from TrafficZoom's proprietary analytics platform.
The average number of vehicles that travel each day over any road in the road network.
10,724
Trucks
Trucks
The percentage of the total traffic volume composed of heavy vehicles.
5.9%
Average travel time
Average travel time
The average time of travel averaged among all vehicles traveling on the road network.
33.9 min
Congestion ratio
Congestion ratio
The rate at which the actual travel time exceeds free-flow travel time, averaged among all roads in the network.
25.2%
Drivers’ average age
Drivers’ average age
Average age of residents in the geographic areas where the vehicle trips originated.
42.1 yrs
Drivers’ average income
Drivers’ average income
Average income of residents in the geographic areas where the vehicle trips originated.
$128,989
Our data indicates an estimated average traffic volume of 10,724 vehicles per day in King County, Washington that results in 40,799,395 vehicle-miles traveled per day (≈14.9 billion per year). The traffic stream is comprised of an average of 1 truck for every 17 vehicles. Typical time spent behind the wheel per trip is 33.9 minutes, which already accounts for delays at signals, intersections, and congestion.
Analytical insight
When compared to the Washington state averages: At 10,724 vehicles per day, the average monitored road in King carries 46% more traffic than the state average of 7,322 vehicles per day - a critical factor for logistics and site planning. Network-wide, King accounts for about 26% of Washington's statewide total, at 40,799,395 vehicle-miles traveled per day (≈14.9 billion per year). At 33.9 minutes, the average travel time is 2% higher than the state level. The congestion ratio of 25.2% is 27% higher, pointing to more pronounced congestion than the state level - crucial for traffic control improvement and logistics planning. At 10,724 vehicles per day, King posts the highest average traffic volume in Washington. 55% of counties in Washington have a shorter average travel time than King's 33.9 minutes.
Highway vs. Non-Highway Traffic Analysis
Highway Traffic
Traffic
Traffic
The average number of vehicles that travel each day over any road in the road network.
42,218
Trucks
Trucks
The percentage of the total traffic volume composed of heavy vehicles.
7.3%
Average travel time
Average travel time
The average time of travel averaged among all vehicles traveling on the road network.
40.8 min
Congestion ratio
Congestion ratio
The rate at which the actual travel time exceeds free-flow travel time, averaged among all roads in the network.
57.4%
Drivers’ average age
Drivers’ average age
Average age of residents in the geographic areas where the vehicle trips originated.
42.1 yrs
Drivers’ average income
Drivers’ average income
Average income of residents in the geographic areas where the vehicle trips originated.
$122,985
A significant volume of traffic in King County, Washington utilizes the highway network. The average highway carries 42,218 vehicles per day, 321% more than the average non-highway road in the same area, which carries 10,034 vehicles per day. That average covers 461 highway road miles divided in 2,372 segments (average segment length 1,026 ft), together carrying 20,228,480 vehicle-miles traveled per day (≈7.4 billion per year). That is the most highway travel volume of any county in Washington. Trucks constitute 7.3% of highway traffic.
Analytical insight
Highway truck concentration here runs 23% lower than the state average, at 7.3% - positioning King as a primarily local traffic hub. For logistics operators, this validates the importance of local access. King's highway truck share (7.3%) is higher than 12% of counties in Washington. King's highway truck count is higher than 91% of counties in Washington, at roughly 3,099 trucks per day.
Non-highway traffic
Traffic
Traffic
The average number of vehicles that travel each day over any road in the road network.
10,034
Trucks
Trucks
The percentage of the total traffic volume composed of heavy vehicles.
4.4%
Average travel time
Average travel time
The average time of travel averaged among all vehicles traveling on the road network.
33.7 min
Congestion ratio
Congestion ratio
The rate at which the actual travel time exceeds free-flow travel time, averaged among all roads in the network.
24.5%
Drivers’ average age
Drivers’ average age
Average age of residents in the geographic areas where the vehicle trips originated.
42.0 yrs
Drivers’ average income
Drivers’ average income
Average income of residents in the geographic areas where the vehicle trips originated.
$133,514
The non-highway road network in King County, Washington supports a substantial volume of traffic. The average non-highway road carries 10,034 vehicles per day, 76% less than the average highway in the same area, which carries 42,218 vehicles per day. That average covers 2,281 non-highway road miles divided in 108,323 segments (average segment length 111 ft), together carrying 20,570,916 vehicle-miles traveled per day (≈7.5 billion per year). Trucks constitute 4.4% of non-highway traffic.
Analytical insight
Compared to highways, non-highway routes see 40% fewer trucks by share. The non-highway congestion ratio of 24.5% is 25% higher than the state level, suggesting slower local mobility than the state average. 55% of counties in Washington see shorter overall travel times than King. King also has the highest average driver income in Washington among trip origins - $128,989. 8% of counties in Washington have a younger driver population than King.
Time-of-Day & Seasonal Patterns
Peak Traffic Windows
Weekday peaks:
AM peak 7:00 AM–12:00 PM and PM peak 3:00 PM–5:00 PM, with volumes reaching approximately 75% higher than the daily average.
Weekend traffic:
Weekend volumes run about 11% below weekday levels.
Seasonal Fluctuation
Busy season:
June–August is the high season, with volumes +5% versus the annual average.
Lowest month:
December is the quietest month, with volumes -5% versus the annual average.
Analytical insight
In King County, Washington, the peak hour concentrates about 7% of the day's traffic, and seasonal swing is mild at +5% in high season.
Traffic Flow Profile Comparison
Metric
King
Washington
Average
Difference
Traffic
10,724
7,322
+46.5%
Truck % (Total Traffic)
5.9%
7.1%
-17.4%
Truck % (Highway)
7.3%
9.5%
-22.8%
Avg. Travel Time
33.9 min
33.2 min
+2.1%
Frequently Asked Questions
The average daily traffic volume is calculated at 10,724 vehicles per day, providing a baseline for daily operations and site assessment.
Yes - King has the highest average driver income of any county in Washington, at $128,989.
Approximately 21% of highway traffic and 3% of non-highway traffic consists of vehicles whose trip originates outside King County, Washington. This indicates that a portion of highway traffic is regional pass-through, while local roads are more representative of resident and commuter activity.
Trucks account for approximately 5.9% of the total traffic mix across all road types, with a significantly higher concentration of 7.3% on highways.
The average travel time for drivers is 33.9 minutes, offering a standard metric for commute and delivery route planning.
Traffic volumes are typically 5% higher during June–August. Volumes drop to their lowest levels in December, averaging 10,192 vehicles per day - a 5% decrease from the annual average.
Drivers on King roads have a median age of 42 years, and the median household income of the neighborhoods trips originate from averages $128,989 - useful context for retail siting and customer profiling.
Data Sources & Methodology
The data presented on this page is derived from TrafficZoom's proprietary analytics platform, which aggregates and normalizes information from multiple sources, including:
Mobile device location data (anonymized and aggregated)
