Chicago-area transit agencies have four years to develop a universal fare card, thanks to a new state law enacted Thursday. Illinois Governor Pat Quinn signed the measure, which will allow passengers to use a single fare card to travel on Chicago Transit Authority, Metra commuter rail, and Pace Suburban Bus. Although the three agencies had already agreed in principle to move to a common card, the law imposes a deadline. One of the challenges will be finding a way to incorporate Metra’s distance-based system, where train conductors punch paper tickets, with the other agencies. CTA already has a smart card in place, and Pace accepts several kinds of tickets and passes. According to the Chicago Tribune, CTA president Forrest Claypool said the agency is already negotiating with a vendor to develop a new fare system. Link to full story in Chicago Tribune.