This lecture introduces the fundamentals of travel demand modeling used in transportation planning and analysis. It is designed for beginners and non-modelers who want to understand how transportation systems are simulated and forecasted.

The course begins by explaining the purpose of travel models and how they are used to predict travel behavior, support infrastructure planning, and evaluate transportation policies. It builds a foundation for understanding how cities estimate future transportation demand.

A key focus is placed on two major modeling approaches: the traditional four-step aggregate model and the modern activity-based disaggregate model. You will learn how each model works, including their inputs, methodologies, and outputs.

The four-step model covers trip generation, trip distribution, mode choice, and route assignment, while the activity-based model focuses on individual travel behavior and daily activity patterns.

The lecture also includes practical examples of both approaches, helping learners understand their real-world applications in transportation planning projects.

In addition, the course compares the strengths and limitations of each modeling approach, highlighting when and why planners choose one method over another.

By the end of this lecture, learners will have a clear understanding of how travel demand models work and how they are used in transportation forecasting and urban planning decisions.