DescriptionThe increased use of location-aware mobile devices has given rise to a need to trigger actions at certain geographic locations. For example, when conducting outdoor vehicular experiments, data frequently needs to be collected within one geographic region. The data collection can be initiated manually, however, it is a tedious process and prone to manual errors. Our framework is designed to use Global Positioning System location updates to automatically trigger actions upon entering and leaving these geographic zones. We mark these zones using trip-boxes, a rectangular box enclosing a geographical area with its orientation towards geographic north and east direction, which can be defined in Google Earth and exported into the trip-box system. The system also uses guard intervals to prevent repeated triggering of trip-boxes due to GPS oscillations. In our evaluation, we experimentally determine the chances of skipping the Trip-Box for a given speed, sampling rate of GPS and the length and the width parameters of the Trip-Box. We conducted experiments for finding a suitable width of the Trip-Box for speeds between 0 - 80mph and by varying sampling intervals from 1 - 5Hz. We also determine the guard flags based on distance traveled and elapsed time calculated after crossing the boundary of the Trip-Box to prevent the repeated triggering of same events. Evaluating experiments using a GPS with 5Hz sampling rate and a standard deviation of 7.5m for a 95 percent accuracy, our results show that on crossing a Trip-Box of width 2m and length 28m is 95 percent reliable when the object moves with a speed less than or equal 20mph.