The following factors and weights shall be used in determining the amount to be allocated to each of the municipalities or municipal counties for street purposes each year:
(1) Total population of each incorporated municipality or the urbanized area of a municipal county, as determined by the most recent federal census figures certified by the Tax Commissioner as provided in section 77-3,119, fifty percent;
(2) Total motor vehicle registrations, other than prorated commercial vehicles, in each incorporated municipality or the urbanized area of a municipal county, as determined from the most recent information available from the Department of Motor Vehicles, thirty percent; and
(3) Total number of miles of traffic lanes of streets in each incorporated municipality or the urbanized area of a municipal county, as determined by the most recent inventory available within the Department of Transportation, twenty percent.