This report provided a general introduction to the use of panel designs in transportation surveys. Through examples drawn from the transportation literature, it illustrated how panel designs could be used to address a variety of transportation issues. The report identified several situations where panel designs are preferable, either because they provide information that cannot be obtained in cross-sectional designs or because they are more efficient than cross-sectional designs. It then discussed the special issues and problems that arise when the same group of individuals is followed over time. The final sections of the report provided guidelines for designing and maintaining a panel survey, and for preparing panel weights for analysis of the data.