This project seeks to develop the requirements, specifications, and initial prototype for an open interface to deliver near real-time transportation information directly to vehicles over the cellular network. Currently, local, regional, and state transportation data are not aggregated or standardized into a single format suitable for use in vehicles. In partnership with public agencies, including the East Central Intergovernmental Association (ECIA), City of Dubuque, City of East Dubuque, City of Asbury, City of Peosta, Iowa Department of Transportation (Iowa DOT), Illinois Department of Transportation (IDOT), Wisconsin Department of Transportation (WisDOT), along with Parsons and Harman Automotive, the project will develop a comprehensive data set capturing a variety of transportation information from the entire Dubuque metropolitan area. This project will integrate the data in a standardized format, build appropriate intelligence to define distribution limits for each piece of data, and develop an open interface to provide this data in near real-time to original equipment manufacturers (OEMs), infotainment system providers, and other third-party data stakeholders. The project will revolutionize how transportation data is collected, shared, and utilized, ultimately supporting complementary data flow, which can provide this valuable data to travelers via direct cellular connection to the vehicle, as well as utilizing a network of roadside units (RSUs) or onboard units (OBUs) in the future. The project aims to provide a complete model dataset and common interface that can be used by other communities across the country, enhancing traffic efficiency, safety, and environmental sustainability.