S&P Global Ratings assigned its 'AA' long-term rating to the Illinois Regional Transportation Authority's (RTA) series 2018A general obligation (GO) working cash notes and 2018B GO bonds. At the same time, we affirmed our 'AA' long-term rating and underlying rating (SPUR) on the authority's previously issued long-term debt. We also affirmed our 'A-1+' short-term rating on the authority's series 2005B extendible reset securities. The outlook on the long-term ratings is stable. The 'AA' rating reflect our view of RTA's: Participation in the large and diverse Chicago metropolitan statistical area (MSA) economy, which generates its sales tax revenue in an area with 8.4 million people in Cook county and five collar counties; First-lien pledge on sales tax revenue, with pledged revenue