The Tolling Transparency Act of 2023 requires the Secretary of Transportation to conduct an economic impact study for any proposed toll facility or toll-based project that undergoes review under the National Environmental Policy Act. This study must examine how tolls would affect businesses, communities, and low-income residents, as well as assess traffic diversion to local roads and the reliability of traffic modeling used to justify the tolls. Importantly, public authorities cannot begin collecting tolls until the economic impact study is completed, and the Secretary of Transportation has the authority to prohibit tolling if the study shows the toll facility would cause unreasonable adverse impacts. The bill affects states and local governments that operate or propose to operate toll roads and bridges, as well as the communities and residents who would pay these tolls. No specific funding or timeline is provided in the legislation, but the requirements apply to any toll project that requires federal environmental review going forward.