ABSTRACT
In many instances, the need arises to study the elapsed time until the occurrence of an event or the duration of an event. Data such as these are referred to as duration data and are encountered often in the field of transportation research. Examples include the time until a vehicle accident occurs, the time between vehicle purchases, the time devoted to an activity (shopping, recreation, etc.), and the time until the adoption of new transportation technologies. Duration data are usually continuous and can, in most cases, be modeled using least squares regression. The use of estimation techniques that are based on hazard functions, however, often provide additional insights into the underlying duration problem (Kiefer, 1988; Hensher and Mannering, 1994).
