605 ILCS 10/1
It is hereby declared, as a matter of legislative determination, that in order to promote the public welfare, and to facilitate vehicular traffic by providing convenient, safe, modern and limited access highways designed for the accommodation of the needs of the traveling public through and within the State of Illinois, that it is necessary in the public interest to provide for the construction, operation, regulation and maintenance of a toll highway or a system of toll highways, incorporating therein the benefits of advanced engineering skill, design, experience and safety factors, to eliminate existing traffic hazards, and to prevent automotive injuries and fatalities, and to create The Illinois State Toll Highway Authority, as an instrumentality and administrative agency of the State of Illinois, and to confer upon and vest in said Authority all powers necessary or appropriate to enable said Authority to carry out the foregoing stated legislative purpose and determination.
605 ILCS 10/1