Both the State Highway Commission and the agricultural and industrial board in exercising the powers granted in this chapter are hereby authorized to accept private donations and public grants which may be available to them, respectively, for the furtherance of the purposes of this chapter. In addition thereto, either or both of such agencies may expend, for the purposes of this chapter, any funds available to them not otherwise specifically designated for a different public purpose. Each of such agencies shall cooperate with other state agencies in carrying out the provisions of this chapter.