The purpose of this study is to enhance an analytical framework for assignment of individual vehicular trips into viable carpooling/vanpooling trips under a set of reasonable restrictions considering spatiotemporal and economic restrictions using the output of the activity-based travel demand model. There are three-fold benefits of research into the carpool system: (1) Evaluate the systemic efficiency and robustness of intelligent carpooling/vanpooling systems; (2) Estimate the economic feasibility in terms of using carpools/vanpools among potential SOV commuters; (3) Estimate the traffic and environmental impact of the system.