The commissioners may employ such assistants as they deem necessary and expend such sums therefor and in the discharge of their duties, including the actual traveling expenses of the members, as they may deem expedient, not exceeding the sum of ten thousand dollars ($10,000.00).
All expenditures shall, from time to time, be certified by the commissioners to the said judge who, if satisfied of the correctness thereof, shall order the payment thereof by the board of chosen freeholders, and the county treasurer shall pay the same out of the funds appropriated or to be appropriated for the maintenance of highways and bridges in the county or out of any unexpended balance.