California is in the midst of a demographic transformation. According to the 2000 U.S. Census, nearly 30 percent of the California population is now foreign-born, more than 50 percent of the population belongs to a minority group, and the elderly (those 65 and older) comprise 11 percent of the population. Demographic forecasts suggest that these patterns will continue. California will continue to attract immigrants from throughout the world and will become increasingly diverse, racially and ethnically, with whites declining as a share of the population from 54 percent in 1995 to 30 to 34 percent in 2025, according to one forecast (Thomas and Deakin 2001). The percentage of seniors will also continue its upward trajectory in the coming decades, reaching over 13 percent by 2025 (Thomas and Deakin 2001). This demographic transformation raises an important question for transportation planners in the state: How can we ensure that the kinds of transportation systems and services we provide adequately meet the needs of our increasingly diverse population? To answer that question, planners need a better understanding of the travel behavior of diverse demographic groups within the state. As a part of a larger project studying the needs, constraints, attitudes, and preferences that influence travel choices and the outcomes of those travel choices among diverse groups in California, this report provides a review of existing literature on the travel behavior among specific demographic groups. In particular, this report provides a review of what is currently known about the travel patterns and transportation needs of the following five demographic groups, nationwide and in California: immigrants, racial and ethnic groups (Blacks, Asians, and Hispanics), Native Americans, elderly, and youth.