
Total Traffic Volume & Performance in Sonoma County, California
Traffic The average number of vehicles that travel each day over any road in the road network. | vehicles per day10,667 |
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Trucks The percentage of the total traffic volume composed of heavy vehicles. | 6.5% |
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Average travel time The average time of travel averaged among all vehicles traveling on the road network. | 32.4 min |
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Congestion ratio The rate at which the actual travel time exceeds free-flow travel time, averaged among all roads in the network. | 28.9% |
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Drivers’ average age Average age of residents in the geographic areas where the vehicle trips originated. | 46.3 yrs |
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Drivers’ average income Average income of residents in the geographic areas where the vehicle trips originated. | $109,586 |
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The average monitored road in Sonoma County, California carries 10,667 vehicles per day. Across its 920 miles of monitored roads, that adds up to 10,645,614 vehicle-miles traveled per day (≈3.9 billion per year). Trucks are a smaller part of the mix than across California: 6.5% against 7.8%.
Busier roads than 81% of counties in California
Sonoma sees 16% lower average daily traffic volume than the state average (10,667 vehicles per day against 12,766), suggesting less demand on each road - a factor worth weighing in site selection and logistics planning. Network-wide, Sonoma accounts for about 1.1% of California's statewide total of vehicle-miles. 81% of counties in California see less traffic than Sonoma's 10,667 vehicles per day.
At 32.4 minutes, the average travel time is 6% lower than the state level. 73% of counties in California have a longer average travel time than Sonoma's 32.4 minutes.
The congestion ratio of 28.9% runs slightly higher than the state level (5% higher).
Highway vs. Non-Highway Traffic Analysis

Highway Traffic in Sonoma County, California
| Traffic | vehicles per day35,966 |
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| Trucks | 8.7% |
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| Average travel time | 33.8 min |
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| Congestion ratio | 62.1% |
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| Drivers’ average age | 46.1 yrs |
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| Drivers’ average income | $107,520 |
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A significant share of driving in Sonoma County, California, 43% of vehicle-miles, happens on highways. The average highway carries 35,966 vehicles per day, 255% more than the average non-highway road in the same area, which carries 10,134 vehicles per day.
Highways make up 15% of the monitored road miles (140 miles, 490 segments), so they carry more than their share: 4,607,973 vehicle-miles traveled per day (≈1.7 billion per year).
By highway travel volume, Sonoma outranks 57% of counties in California.
Lower highway truck share than 67% of counties in California
Highway truck concentration here runs 16% lower than the state average, at 8.7%. Highways here mostly serve passenger trips, so local access matters more than long-haul routing for logistics operators.
Sonoma's highway truck share (8.7%) is lower than 67% of counties in California. Sonoma's highway truck count is higher than 51% of counties in California, at roughly 3,125 trucks per day.

Non-highway Traffic in Sonoma County, California
| Traffic | vehicles per day10,134 |
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| Trucks | 4.9% |
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| Average travel time | 32.3 min |
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| Congestion ratio | 28.2% |
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| Drivers’ average age | 46.4 yrs |
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| Drivers’ average income | $110,966 |
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A little more than half of the driving in Sonoma County, California happens on local roads: 57% of all vehicle-miles. A typical local road sees 10,134 vehicles per day.
Spread over 780 miles and 23,267 segments, 85% of the road network, local roads carry a lighter load per mile: 6,037,642 vehicle-miles traveled per day (≈2.2 billion per year). The truck share on non-highway roads is 4.9%.
Drivers from higher-income areas than 75% of counties in California
Compared to highways, non-highway routes see 44% fewer trucks by share.
Non-highway congestion (28.2%) runs slightly higher than the state level (6% higher).
Sonoma's average driver income is higher than 75% of counties in California. 60% of counties in California have a younger driver population than Sonoma.