Abstract:
The day-to-day variability of journey-to-work trips, including departure time, route choice, and trip-chaining behavior, was examined with Global Positioning System-based disaggregate morning commute data for 56 drivers during a 1-week period. Data were collected from the ongoing instrumented vehicle projects in Atlanta sponsored by NHTSA and FHWA. The study examines alternative measurements of the day-to-day variability of the commute pattern. While commuting trips are often thought to be highly repetitious and therefore highly predictable trips, research results indicate that commuters change departure times more frequently than routes, and trip chaining significantly affects commuters' departure time and route choice behavior. This study begins to explore definitions and relationships that will be necessary to better understand the day-to-day commute dynamics.