Transportation Network Modeling

**Agent #

based modeling (ABM):** A type of transportation network modeling that simulates the actions and interactions of individual agents (e.g., vehicles, pedestrians) within a transportation system. ABM can capture emergent behavior and complex dynamics that may not be evident in other modeling approaches.

**Demand modeling #

** The process of estimating the number of travelers, their origins and destinations, and their travel preferences in a transportation network. Demand models can be static or dynamic, and can inform the design and operation of transportation systems.

**Dynamic traffic assignment (DTA) #

** A type of transportation network modeling that simulates the movement of vehicles through a network in real-time, taking into account changing traffic conditions, such as incidents, weather, and demand. DTA can provide insights into the performance of transportation systems and inform real-time traffic management strategies.

**Emission modeling #

** The process of estimating the amount and type of emissions produced by vehicles in a transportation network. Emission models can inform air quality management and climate change mitigation efforts.

**Equilibrium assignment #

** A type of transportation network modeling that seeks to find the balance between travel demand and supply in a network, such that no traveler can improve their journey by switching routes or modes. Equilibrium assignment can inform transportation infrastructure investment and planning.

**Freight modeling #

** The process of estimating the movement of goods through a transportation network, including the types, volumes, and origins and destinations of commodities. Freight models can inform freight infrastructure investment and planning.

**Intelligent Transportation Systems (ITS) #

** A broad field that involves the application of advanced technologies, such as sensors, communication systems, and data analytics, to improve the safety, efficiency, and sustainability of transportation systems.

**Microsimulation #

** A type of transportation network modeling that simulates the movement of individual vehicles and travelers through a network, taking into account their characteristics, behaviors, and interactions. Microsimulation can provide detailed insights into the performance of transportation systems and inform traffic management strategies.

**Microscopic traffic flow theory #

** A theoretical framework that describes the behavior of individual vehicles and travelers in a transportation network, including their acceleration, deceleration, and lane changing behaviors. Microscopic traffic flow theory informs microsimulation and other types of transportation network modeling.

**Network loading #

** The process of assigning travel demand to a transportation network, taking into account the capacity and performance of the network. Network loading can inform transportation infrastructure investment and planning.

**Queueing theory #

** A mathematical framework that describes the behavior of queues, such as those that form at traffic signals or intersections. Queueing theory informs traffic signal timing and other traffic management strategies.

**Meso #

scale modeling:** A type of transportation network modeling that simulates the movement of vehicles and travelers through a network at a meso-scale, which is larger than a micro-scale but smaller than a macro-scale. Meso-scale modeling can provide insights into the performance of transportation systems and inform traffic management strategies.

**Macroscopic traffic flow theory #

** A theoretical framework that describes the behavior of traffic flow at a macro-scale, including aggregated traffic variables such as speed, flow, and density. Macroscopic traffic flow theory informs macroscopic traffic simulation and other types of transportation network modeling.

**Public transit modeling #

** The process of estimating the demand for and supply of public transit services in a transportation network. Public transit models can inform transit infrastructure investment and planning.

**Stochastic user equilibrium (SUE) #

** A type of transportation network modeling that seeks to find the balance between travel demand and supply in a network, taking into account the randomness of travelers' route choices. SUE can provide insights into the performance of transportation systems and inform traffic management strategies.

**Traffic flow theory #

** A theoretical framework that describes the behavior of traffic flow in a transportation network, including the interactions between vehicles and travelers. Traffic flow theory informs traffic simulation and other types of transportation network modeling.

**Transportation network company (TNC) #

** A company that provides prearranged transportation services for compensation using an online-enabled platform to connect passengers with drivers using their personal vehicles. TNCs, such as Uber and Lyft, have transformed the transportation landscape in many cities around the world.

**Transportation network modeling #

** The use of mathematical and computational models to simulate the movement of vehicles and travelers through a transportation network, with the aim of informing transportation infrastructure investment, planning, and management.

**Travel demand forecasting #

** The process of estimating the future demand for travel in a transportation network, taking into account demographic, economic, and land use trends. Travel demand forecasting can inform transportation infrastructure investment and planning.

**Travel time reliability #

** A measure of the consistency and predictability of travel times in a transportation network, which is an important factor in travelers' route choices and transportation system performance.

**Traffic simulation #

** The use of computer models to simulate the movement of vehicles and travelers through a transportation network, with the aim of evaluating the performance of the network and informing traffic management strategies.

**Urban mobility planning #

** A comprehensive and integrated approach to planning and managing urban transportation systems, taking into account the needs and preferences of all travelers, including pedestrians, cyclists, and public transit users.

**Vehicle routing problem (VRP) #

** A type of optimization problem that seeks to find the optimal routes for a fleet of vehicles to serve a set of customers, taking into account constraints such as vehicle capacity, travel time, and distance. VRP is an important problem in freight transportation and logistics.

**Visit density function #

** A measure of the concentration of travelers in a transportation network, which can inform the design and operation of transportation systems.

**Wardrop's principle of user equilibrium #

** A fundamental concept in transportation network modeling, which states that in a transportation network at equilibrium, no traveler can improve their journey by switching routes. Wardrop's principle underlies many types of transportation network modeling, including static and dynamic traffic assignment.