Motor Vehicle Fuel Tax

In the State of Washington, the state motor vehicle fuel tax (MVFT), currently 49.4 cents/gallon, is shared among the cities, counties and the state Department of Transportation. This includes a dedication of a portion of the MVFT to grant programs managed by the County Road Administration Board (CRAB) and the Transportation Improvement Board (TIB). The most recent MVFT increase was primarily dedicated to the Transportation Partnership Account (TPA) utilized for legislatively selected transportation projects (RCW 46.68. 122-124)

Between the Rural Arterial Program (RAP), the County Arterial Preservation Program (CAPP), and the regular county distribution, counties receive a share approximately equal to 5.96 cents per gallon, plus a small amount from the TPA dedicated to CAPP. The county total share of the MVFT is approximately 16% of the net state fuel taxes collected. State law describes the basic processes and authorities to perform the biennial and annual update calculations, with CRAB having the responsibility to perform these calculations pertaining to the counties' share of MVFT.

During the mid-1950's, the county fuel tax regular, or "normal", distribution formula was significantly changed, creating what is known as the 10-30-30-30" formula pictured in the right column of this page. Since then there have been only a few minor revisions. The counties' share of the state motor vehicle fuel tax (less administrative, island county refunds and special studies deductions) is divided among the 39 counties as follows: 10% shared equally, 30% based on "equivalent" population, 30% based on "road costs" and 30% based on "money needs.

Gas Tax Control Fields

Under state law gas tax control field information is collected to help the County Road Administration Board estimate road replacement and maintenance costs for county fuel tax allocations. Control fields are those fields utilized for the computation of gas tax allocations in accordance with (RCW 46.68.124). The control fields are: Unique identifier (county road number, beginning milepost, ending milepost), jurisdiction, length, function class, surface type, surface width, right and left shoulder type, right and left shoulder width, and average daily traffic volume. All control field updates are subject to review, approval and must be validated by the County Road Administration Board.

County Gas Tax Distribution

The current county gas tax formula has been in effect with only minor revisions since 1954 and last amended in 1988.

motor vehicle fuel tax distribution factors

The final report to the Legislature in 1954 discussed the formula and how it addressed needs and concluded that the current formula was the most equitable. In 1985 CRAB was given the responsibility in determining each county's share of the gas tax, which includes the biennial and annual calculations:

There are four factors used in the calculations:

Equal Distribution (10%)
Equivalent Population (30%)
Annual Road Costs (30%)
Annual Money "Needs" (30%)


A valuable reference tool is WSDOT's Transportation Manual (State Taxes and Fees). Click here to view the manual. Click on page 45 in the table of contents for Motor Vehicle Fuel Tax information.

Revenue forecast links of the WSDOT web-site:

Revenue forecast links on the OFM:website:

Where does the fuel tax go?

The chart below notes the Motor Vehicle Fuel Tax increase since 1921.

Washington State Motor Fuel Excise Tax History and Future
Year Amount Year Amount Year Amount Year Amount
1921 1.0¢ 1967 9.0¢ 1990 22.0¢ 2016 49.4¢
1924 2.0¢ 1977 11.0¢ 2003 28.0¢ 2019 ?
1929 3.0¢ 1979 12.¢ 2005 31.0¢    
1931 4.0¢ 1981 13.5¢ 2006 34.0¢    
1933 5.0¢ 1983 16.0¢ 2007 36.0¢    
1949 6.5¢ 1984 18.¢ 2015 44.5¢    

1.0¢ in 1921 with inflation = 13.0¢in 2018

Source: WSDOT Fuel Tax Analysis