The State Department of Education shall calculate the cost of transportation in school districts by ascertaining the average cost per pupil in average daily attendance of transported pupils in school districts classified in different density groups as determined by the State Department of Education. Based on these calculations, the State Department of Education shall develop a scale for determining the allowable cost per pupil in different density groups, which scale shall provide greatest allowance per pupil transported in school districts with lowest densities and smallest allowance per pupil in school districts with highest densities. The total allowance in the adequate education program for transported children for any school district for the current year shall be the average daily attendance of the transported children for the nine (9) months of the prior year, multiplied by the allowance per transported pupil as provided herein. However, the State Department of Education is hereby authorized and empowered to make proper adjustments in allotments, under rules and regulations of the State Board of Education, in cases where major changes in the number of children in average daily attendance transported occur from one (1) year to another as a result of changes or alterations in the boundaries of school districts, a change in or relocation of attendance centers, or for other reasons which would result in major decrease or increase in the number of children in average daily attendance transported during the current school year as compared with the preceding year. Moreover, the State Board of Education is hereby authorized and empowered to make such payments to all districts and/or university-based programs as deemed necessary in connection with transporting exceptional children as defined in Section 37-23-3. The State Board of Education shall establish and implement all necessary rules and regulations to allot transportation payments to university-based programs. In developing density classifications under the provisions hereof, the State Department of Education may give consideration to the length of the route, the sparsity of the population, the lack of adequate roads, highways and bridges, and the presence of large streams or other geographic obstacles. In addition to funds allotted under the above provisions, funds shall be allotted to each school district that transports students from their assigned school or attendance center to classes in an approved vocational-technical center at a rate per mile not to exceed the average statewide cost per mile of school bus transportation during the preceding year exclusive of bus replacement. All such transportation must have prior approval by the State Department of Education.