A. In addition to all other taxes imposed by this chapter, there is hereby levied an additional tax per gallon on diesel fuel. Beginning July 1, 2021, the rate of such tax shall be 2.03 percent of the statewide average wholesale price of a gallon of diesel fuel for the applicable base period, excluding federal and state excise taxes, as determined by the Commissioner.

B. The Commissioner shall use the period from December 1 through May 31 as the base period for such determination for the immediately following period beginning July 1 and ending December 31, inclusive. The period from June 1 through November 30 shall be the next base period for the immediately following period beginning January 1 and ending June 30, inclusive. In no case shall the average wholesale price computed for purposes of this section be less than the statewide average wholesale price of a gallon of diesel fuel on February 20, 2013.

C. Blended fuel that contains diesel fuel shall be taxed at the rate levied on diesel fuel.

D. The tax imposed by this section shall be collected in the same manner as other taxes imposed pursuant to this chapter.

E. The revenues generated by the tax imposed by this section shall be distributed as follows: (i) an amount equal to such net revenues multiplied by a ratio of the vehicle miles traveled on Interstate 81 by vehicles classified as Class 6 or higher by the Federal Highway Administration to the total vehicle miles traveled on all interstate highways in the Commonwealth by vehicles classified as Class 6 or higher by the Federal Highway Administration into the Interstate 81 Corridor Improvement Fund established pursuant to § 33.2-3601; (ii) an amount equal to such net revenues multiplied by a ratio of the vehicle miles traveled on the portion of interstate highways located within the boundaries of Planning District 8 by vehicles classified as Class 6 or higher by the Federal Highway Administration to total vehicle miles traveled on all interstate highways in the Commonwealth by vehicles classified as Class 6 or higher by the Federal Highway Administration into the Northern Virginia Transportation Authority Fund established pursuant to § 33.2-2509; and (iii) all remaining net revenues to the Commonwealth Transportation Board for use for operational improvements and other enhancements to improve the safety and reliability of, and travel flow along, interstate highway corridors in the Commonwealth. The Board shall ensure that for any interstate highway with more than 10 percent of total interstate truck vehicle miles traveled that the total long-term expenditure for each such interstate highway is approximately equal to the proportional revenue subject to clause (iii) that is attributable to such interstate highway.

2019, cc. 837, 846.