The Illinois Road and Transportation Builders Association (IRTBA) has served as the leading transportation industry trade association in Illinois since 1938. IRTBA member firms design, build, and maintain the state highways, transit systems, railways, and aviation systems. The core purpose of IRTBA is to advance and promote the transportation design and construction industry in Illinois. On behalf of the 350+ member firms, we hope you find our site helpful in providing background on our Association as well as answering any questions you have on transportation issues in Illinois.