In Bibb County, the county commission may expend funds accruing to the county from the County Government Capital Improvement Fund in any amount up to 50 percent for the operation of the Bibb County Highway Department, including, but not limited to, expenses for that portion of any costs directly related to the operation of the highway department such as liability insurance, workers' compensation insurance, and bond payments. Any expenditures of the funds shall be approved by the county commission prior to expenditure.