Theory# This section describes the theory and ideas behind POLARIS’ components and provides references to published work. Contents# Demand Model Overview Contents Assignment and Routing Models Routing Multimodal Routing, Assignment, and Simulation Traffic Flow Model Brief Network Description Key parameters applicable to all supported models Further Reading Shared Mobility Overview Shared Mobility Operator File TNC Operator TNC Vehicle TNC Assignment TNC Repositioning Dynamic Ride-Sharing First-Mile Last-Mile (FMLM) Helpful Hints Modes Freight Freight Framework Overview