(1) One half on a county road mileage basis, as provided in subsection (b)(1) of this section; and

(2) One half on a motor vehicle registration basis, as provided in subsection (b)(2) of this section.

(b) The Administration shall allocate for the account of each county, out of the highway user revenues to be distributed to the counties under § 8-403 of this subtitle, the county’s share, to be determined by adding:

(1) The amount that results from applying to one half of these highway user revenues the ratio that, as of December 1 of the preceding calendar year, the total mileage of county roads in the county, not including the total mileage of county roads in eligible municipalities in the county, bears to the total mileage of county roads in all of the counties, not including the total mileage of county roads in eligible municipalities in the State; and

(2) The amount that results from applying to one half of these highway user revenues the ratio that, as of December 1 of the preceding calendar year, the total number of motor vehicles registered to owners having addresses in the county, not including motor vehicles registered to owners having addresses in eligible municipalities in the county, bears to the total number of motor vehicles registered to owners in all the counties, not including motor vehicles registered to owners having addresses in eligible municipalities in the State.