Vehicles

This page describes the transportation sector growth and its' environmental impact. King County has worked to reduce the emissions created by vehicles at the public, commercial, industrial and municipal levels. The emissions data presented on this page was calculated using a metric called "vehicle miles traveled", or VMT. VMT is calculated using data from the Puget Sound Resource Council (PSRC), a group that collects transportation data for the region. PSRC provides estimates of vehicle miles traveled in four vehicle categories (passenger cars, heavy trucks, medium trucks, and transit buses) and calculates resulting emissions for each group at the County level. Combining PSRC's estimates with each city's total VMT data via the Bellevue-Kirkland-Redmond model, or BKR model, yielded an estimate of the emissions created on our roadways by vehicle type. In the case of Mercer Island, older local PSRC data was extrapolated to estimate the current VMT. Efforts to reduce the environmental impact of transportation have focused on shortening commutes, reducing the fuel intensity of cars, fuel switching, and encouraging use of public transportation.

Which Vehicle Type Contributes the Most Emissions?

The vast majority of vehicle emissions created in King County are from passenger cars. PSRC models for the composition of vehicles types in each category, with various fuel efficiency and fuel type.

King County Emissions by Vehicle Type, 2014-2016

How Many Miles on Average Are We Driving?

This chart shows the annual vehicle miles traveled by the average person in each of our four cities and in all of King County. The blue benchmark displays the average vehicle miles traveled by a Washington citizen in the year 2016.

Vehicle Miles Traveled Per Capita

How Much Emissions Are Our Vehicles Creating?

Total vehicle emissions have increased slightly for all four cities, and King County as a whole, since 2014. This could be due to the continuous rise in population numbers for each city. King County's large emissions totals are due to larger population and vehicle totals compared to the four cities. While the first chart shows little reduction in total emissions, the second chart projects a different story. Per capita vehicle emissions have decreased or had no change since 2014 in each of the four cities and in the county as a whole. The blue benchmark shows the King County average per capita vehicle emissions from 2010.

Transportation Emissions in Metric Tonnes

Transportation Per Capita Emissions in Metric Tonnes

More Bus Rides Equate to Lower Emissions

From 2011 to 2016, transit boarding in King County have increased nearly 8%. Using methods of public transportation instead of driving in a car both reduces emissions and saves money! Over the past several years, King County and Sound Transit have pushed an initiative to increase bus and rail transit regionally. By 2024, Sound Transit states that light rail service will extend to Mercer Island, Bellevue, Redmond and parts of Kirkland. Along with more efficient travel, this expansion will provide more opportunities for transit oriented housing developments to arise.

K4C

King County Cities Climate Collaboration Dashboard