; and (2) for medium- and heavy-duty trucks, a per-mile user fee that is equivalent to— (A) the average annual taxes imposed by sections 4041 and 4081 of such Code with respect to diesel fuel, divided by (B) the total vehicle miles traveled by medium- and heavy-duty trucks. Taxes shall only be taken into account under the preceding sentence to the extent taken into account in determining appropriations to the Highway Trust Fund under section 9503(b) of such Code, and the amount so determined shall be reduced to account for transfers from such fund under paragraphs (3), (4), and (5) of section 9503(c) of such Code. (e) Volunteer participants The Secretary of Transportation, in coordination with the Secretary of the Treasury, shall— (1) ensure, to the extent practicable, that an appropriate number of volunteer participants participate in the pilot program; and (2) issue policies to— (A) protect the privacy of volunteer participants; and (B) secure the data provided by volunteer participants. (f) Public awareness campaign The Secretary of Transportation may carry out a public awareness campaign to increase public awareness regarding a national per-mile user fee, including distributing information related to the pilot program carried out under this section, information from the State surface transportation system funding pilot program under section 6020 of the FAST Act ( 23 U.S.C. 503 note). (g) Revenue collection The Secretary of the Treasury, in coordination with the Secretary of Transportation, shall establish a mechanism to collect per-mile user fees established under subsection (d) from volunteer participants. Such mechanism— (1) may be adjusted as needed to address technical challenges