The Supervisor of Safety shall enforce all the laws of this State and, within the municipalities in his county, the ordinances of such municipalities relating to the regulation of motor vehicle traffic and the promotion of safety on public highways. The Supervisor of Safety shall advise the county board as to contracts negotiated regulating traffic of parking areas of schools, hospitals, commercial and industrial facilities, shopping centers and apartment complexes outside any municipality of said county, and shall act as its representative and agent in connection with the execution of such contracts. In those instances where contracts are being negotiated between municipalities and schools, hospitals, commercial and industrial facilities, shopping centers and apartment complexes outside the corporate limits, the Supervisor of Safety shall advise the county board. All such contracts shall be negotiated in the manner of section 11-209 of The Illinois Vehicle Code. Subject to the approval of the county board, the Supervisor of Safety may appoint assistants to aid him in carrying out his duties. The Supervisor of Safety shall cooperate with the State and Federal governments and agencies thereof in programs designed to promote safety on highways.
     The Supervisor of Safety in counties of less than 1,000,000 inhabitants may enter into cooperative contractual agreements with school districts in his county, under which the school district hires, compensates and is liable for one or more school crossing guards, and the Supervisor of Safety, as sheriff of the county, appoints any such guard as an auxiliary deputy, in the manner and under the terms of Sections 3-6001 through 3-6032.
     This Section is not a prohibition upon the contractual and associational powers granted by Article VII, Section 10 of the Illinois Constitution.