; (2) to ensure that Federal taxes collected from nonhighway recreation are appropriately returned to the States for the recreational trails program, an accurate estimate of the total amount of nonhighway fuel taxes collected is necessary; and (3) an accurate study to produce a best available estimate of the total amount of nonhighway recreational fuel taxes received by the Secretary of the Treasury will help inform Congress in continuing to authorize the recreational trails program. 3. Definitions In this Act: (1) Administrator The term Administrator means the Administrator of the Federal Highway Administration. (2) Highway Trust Fund The term Highway Trust Fund means the Highway Trust Fund established by section 9503(a) of the Internal Revenue Code of 1986. (3) Nonhighway recreational fuel taxes The term nonhighway recreational fuel taxes means taxes under section 4041 and 4081 of the Internal Revenue Code of 1986 with respect to fuel used in vehicles on recreational trails or back country terrain (including vehicles registered for highway use when used on recreational trails, trail access roads not eligible for funding under title 23, United States Code, or back country terrain). (4) Recreational trails program The term recreational trails program means the recreational trails program under section 206 of title 23, United States Code. (5) Secretary The term Secretary means the Secretary of Transportation. 4. Nonhighway recreational fuel study (a) Assessment