Abstract: Smart in-vehicle decision support system has been developed to address current challenges and offers a new approach to make right stop/go decisions for vehicles to drive through a signalized intersection. The methods and systems described herein exploit a novel conceptualization of the decision support problem as an integration process, where a decision support model takes advantages of vehicle-to-infrastructure communications and fuses the inputs from vehicles and intersection, which comprise key information of vehicle motion, vehicle-driver characteristics, signal phase and timing, intersection geometry and topology, and the definitions of red-light running, to explore a more complete variable space of physical and behavioral information and provide safer and more efficient decision supports to vehicles driving through a signalized intersection than the previous methods and systems.