This document provides an overview of key concepts in transportation planning. It defines transportation as the moving of people and discusses how transportation occurs through various modes including private vehicles, public transit, biking and walking. It also examines who is involved in transportation systems like departments of transportation and planning organizations. The document reviews why people travel for different trip purposes and discusses transportation trends related to traffic, safety, accessibility, pollution and congestion. It concludes by outlining strategies like density, proximity, mixed uses and connectivity that can make transportation systems more efficient, sustainable and improve public health.