The biggest barrier to expanding implementation of traffic signal priority is money, the report said. Many of the city’s traffic lights are decades old and need to be replaced before traffic signal priority could be added, and neither the city’s transportation department nor the CTA has a dedicated source of funding for this, so they are left to pursue grants. The Regional Transportation Authority was able to get a $40 million federal grant for the CTA to implement traffic signal priority on South Ashland and Western avenues, and for Pace to install it on a few suburban routes.